Abstract This paper presents the results of empirical research conducted in context of a broader study on the use of experts in international disputes. An analysis of the interviews conducted and responses received from questionnaires as part of this empirical research sheds light on various aspects of expert involvement in international disputes, revealing trends that are not discernible from a textual or casuistic approach. The analysis in this paper also demonstrates interesting divergences as well as common approaches to expert use in different international judicial fora, and among different actors in the judicial process - judges, counsel or experts themselves. The paper concludes that no single unified regime can be identified for experts in international law, variances exist in connection with the forum considered. At the same time, the empirical study reveals universal characteristics in expert use mainly to be found in due process requirements. 1. INTRODUCTION AND RESEARCH METHODOLOGY This contribution intends to present some of the results of a study directed towards experts in international dispute settlement, which comprised the sending of questionnaires and involved conducting of interviews. This study constitutes the empirical aspect of a broader research project on experts conducted at the Faculty of Law of the University of Geneva.1 The limited scholarship and study on the use of experts in international courts and tribunals prompted the initiation of this 4-year long project by the authors of this contribution. The objective of the research project is to gain extensive and detailed knowledge regarding the expert in international dispute settlement.2 It intends to provide a comprehensive vision of experts in international disputes, and construct an overall ‘map’ of expert use in international law, in its texts and practices. Receiving and analysing the questionnaire responses was preceded by a phase of compilation and examination of the primary sources to identify a theoretical framework. This phase revealed a degree of similarity among the legal provisions surrounding experts before international courts and tribunals. These provisions are characterized by their broad scope and flexibility; they have therefore made space for a variety of practices to evolve over time. Consequently, difficulties experienced by judges, counsel or experts, when engaging with technical data in a legal dispute, are largely invisible to an observer outside the system. Critical to an in-depth understanding of the subject was the supplementing of case analysis with the experience of key players in the field. On the one hand, the questionnaires were meant to enrich the understanding of the existing theoretical data, and on the other hand, provide certain considerations arising from the practice, which are not apparent from solely studying the texts. By way of example, the interviews were not designed to reveal the prevalence of the party’s expert over the expert appointed by the judge, but rather to inform the researchers about reasons driving the limited use of the latter. The particular aims of the project prompted a specific research methodology. The goal of the questionnaires and interviews was to understand the perception and appreciation of the expert in international dispute settlement by key players on the judicial scene. This goal was conducive to adopting a qualitative methodology for this part of the research. The qualitative empirical approach, not frequently employed in the international legal field, may be summarized as follows: “a ‘qualitative observation’ identifies the presence or absence of something, in contrast to ‘quantitative observation’, which involves measuring the degree to which some feature is present.”3 The investigation ‘attempt[ed] to capture and categorize social phenomena and their meanings’4 and was not relying on quantitative measurement and statistics. This qualitative approach implied interviewing a limited number of people ‘in order to capture a spectrum of viewpoints and experiences …’,5 an endeavour that would have been practically impossible were one to receive several hundred opinions. This is in opposition to a quantitative method which relies on the identification and ‘collection of large quantities of data from an entire population […] in a systematic fashion’6 so as to generalize the conclusions. As a consequence, with regard to data collection, the participants were selected following the ‘purposeful sampling’7 technique due to their specific and personal extensive experience and knowledge of experts in international litigation. These individuals, at advanced stages of their careers and renowned in their respective fields, provided ‘rich sources of information’8 justifying in-depth analysis of their responses, in opposition to an enumeration and quantification of simple opinions. It is rare to have a completely qualitative (or completely quantitative) research design, and some limited quantitative elements have been used in the design of this research, by considering basic and logical considerations of representativity besides the personal importance of the individual. First, the categories of actors interviewed reflect the different capacities of involvement in the judicial process: adjudicators, counsel, registry staff and experts. The identity of the consulted individuals has also been determined considering three other objective criteria: forum of involvement, legal tradition of origin and type of dispute involved in. An overall number of 61 responses were received and analysed. The fora considered were the International Court of Justice (ICJ), International Tribunal for the Law of the Sea (ITLOS), arbitral tribunals established under Annex VII of the UN Convention on the Law of the Sea, World Trade Organization (WTO) panels and Appellate Body, and arbitrations conducted under the auspices of the International Centre for the Settlement of Investment Disputes (ICSID), the Permanent Court of Arbitration (PCA) and other inter-State arbitrations. The questionnaires were not meant to lead to a precise statistical representation of opinions in the international legal community in a numerical way, but to allow the researchers to grasp the existing diversity of opinions and perspectives.9 Due to the large number of questions and the sophistication in assessment of the responses along with the different perceptions of the legal institutions, a quantitative analysis in terms of statistics would make little sense, even if possible. However, if the findings do not permit undue generalizations, or assessment, in a statistical manner, of the prevalence of one or another opinion or analysis presented, the relative importance of the sample allows identification of trends and common conceptions, or clear rejections. Specific questionnaires were crafted for each category of individuals before each forum, according to the theoretical analysis conducted in advance and the legal specificity of each forum. The number of questions ranged from 42 to 62, divided into three main sections intended to chronologically cover every aspect of each phase of expert involvement in judicial proceedings.10 The interview responses, some written, and some recorded, have all been received under the Chatham House Rule, maintaining anonymity of the interview subjects. The data collected through these techniques required analysis and interpretation from the researchers, since it was not, as noted earlier, capable of a clearly measurable appraisal and representation. As no specific hypothesis was tested, the research method employed is mainly inductive. The analysis of each set of questionnaire responses was completed individually, followed by all the responses of each category of actors for a specific forum. This analysis has shown that there is a diversity of opinions on some fundamental questions regarding expert use. The diversity is not only of opinions but also of perspectives. Thus, there appears to be great disagreement on certain aspects of the law and procedure, while certain key legal concepts relevant to experts have different meanings for different individuals involved in the same legal system. Disagreements range from the roles played by party-appointed or court-appointed experts, the use of invisible experts, and the merits of cross-examination, to the definitions of terms such as independence, impartiality and neutrality. Disagreements were also noted regarding the meanings of essential legal concepts like standard of review, admissibility of expert evidence, scientific uncertainty and the nature of the judicial function. The primary endeavour in analysing these interviews has been to reach a balance between highlighting individual opinions and showcasing a combination of all opinions, thereby trying to reach the most objective result possible. The results of the analysis will thus be presented by forum. The project researchers will examine the responses from participants in the judicial process of the International Court of Justice (Section 2), the International Tribunal for the Law of the Sea (Section 3), those who participate in investment arbitration proceedings (Section 4) and WTO dispute settlement participants ( Section 5). The article concludes with lessons drawn from the above-mentioned survey, and avenues for further research and analysis that have been opened in light of this study (Section 6). 2. INTERNATIONAL COURT OF JUSTICE This section provides an overview of some salient aspects of the insights gained from analysing the responses received from different categories of individuals involved with disputes before the International Court of Justice—some former and present judges of the Court and members of its registry (Section A), counsel who have appeared or appear before the ICJ (Section B), and those who have appeared as experts, in different capacities, in disputes before the Court (Section C). A final part of this section brings together the various threads of opinion from these three categories, those in consensus and those in opposition, to provide a consolidated view of the ICJ (Section D). A. ICJ Judges and Registry An examination of the opinions of judges of the ICJ brought up varied responses and diverse perspectives. Legal cultural factors seem to play an important role in informing the answers to many questions—resulting not only in differing opinions, but also, at times, different ways of comprehension of the same concept. However, several points of convergence can be identified in the opinions regarding expert use at the Court and on some occasions, unanimous views. Indeed, beyond the diversity, a common approach can be seen with regard to definitions, presuppositions and overall assessment of certain issues (though the justification may differ). The approach is also unified by its marked difference from that of the counsel and expert responses. Judges, both present and former, betray, in general, what could be termed a traditional or conservative approach from their responses. They prefer the status quo, stressing a wide scope for interpreting the Statute of the Court and its Rules. According to them, therefore, the present legal framework for experts seems to work well, and there is no need for change in that respect. However, paradoxically, their responses also reveal a preference for more precision in the Rules, for the purposes of handling expert evidence, implying clearer guidance to both the Court and the parties. The traditional approach is also reflected in the fact that most respondents are unacquainted with new techniques and procedures of dealing with experts11 and perhaps because of this unfamiliarity, are also unenthusiastic about incorporating them into the oral proceedings. Responses also reveal the limited consideration given to the definition of the role of experts (and consequent duties and attributes), whether appointed by a party or the Court.12 While dwelling on these questions, responses are a mixed bag of prescriptive and descriptive, making it difficult to find a clear trend on the existing role, and the ideal role that each category of expert should perform. Broadly, respondents note that the role of the party-appointed expert includes a presentation of the facts, a personal assessment of these facts and a pervasive requirement of the quality of honesty or fairness (without reference to independence or impartiality). A Court-appointed expert’s role is the same according to some, except for a greater need for objectivity. According to others, this expert has a role different from that of a party’s expert, because of the absence of cross-examination. Even when absent in the respondents’ definition of the role of experts, the requirements of independence and impartiality are often considered critical to, among other things, assessing expert evidence. However, the discussion on these ethical requirements reveals that not much thought has been given to defining the terms, nor have procedures been developed or even considered for determining their existence. It appears that ‘no real difference’ is made between the concepts of independence and impartiality, the two terms being used most often interchangeably. Those who attempt to define independence, do so in terms of ‘lack of connections with the party’ or ‘not acting as a form of counsel when they testify’. A respondent also believes that these requirements are only applicable in case of court-appointed experts and do not apply to party-appointed experts. In contrast with existing practice,13 all judges interviewed considered the possibility of using such experts, while some even actively supported greater use of ex-curia experts. In this context, the Corfu Channel case,14 the first decided case by the ICJ, and the last that saw the Court appointing experts of its own accord15 until 2016,16 was cited with approval as an example to follow. At the same time, there is a prevalent fear of delegation of the judicial duty to court-appointed experts, a possibility that could arise if the expert receives too wide a mandate in terms of fact-finding or assessment of scientific evidence or if her opinion is incorporated into the decision without application of the legal mind. Thus, in attempts to gain a clear picture on an aggregated analysis of the responses, questions such as the duty of the party’s expert (to the party or the Court), the independence requirement of a party’s expert (whether the same as that of the Court-appointed expert) and the task of an ex-curia expert (whether to review party evidence or provide new evidence), remain to be clarified. This lack of precision and divergences regarding such questions is intriguing, since these definitions form part of the expert regime and could affect questions of evidence such as admissibility. A particular perspective on experts fantômes17 emerges from the responses. While largely emphasizing that the use of Court-appointed experts needs to be transparent, the respondents specify a certain kind of expert that the Court appoints. According to them, those that assist the Court with ‘technical details’ such as drawing a land or maritime boundary, ‘their expertise plays no role in the determination of the dispute’. Thus, the need for transparency in appointment and other processes need not apply to them. B. ICJ Counsel It is clearly discernible in the responses received that almost every person interviewed in this category, as opposed to the judges, adopted very distinctive and identifiable approaches towards issues of expert use, that seem to reflect their professional backgrounds. This highlights the relevance of cultural factors in our analysis as also emphasized by one of the respondents. There is a diversity of opinions on certain fundamental questions and even disagreement on the meaning of important terms. This diversity is in itself enlightening, revealing the absence of a clear and established framework for the use of experts, leaving substantial leeway for personal understanding, informed by personal experience and interpretation. Considering this diversity of views, the points of agreement are even easier to identify. All respondents consider that de facto or de jure, the party’s expert behaves as an advisor for the party. Indeed, some respondents point out that they often collaborate with experts in framing their arguments. They are generally in agreement on the distinct roles of Court-appointed and party-appointed experts, only the former being appointed to assist the Court. Interestingly, respondents emphasize the duty of honesty for party-appointed experts, while at the same time requiring this expert to support the party’s position. There is moreover a quiet acknowledgement that the knowledge brought by the party-appointed expert could be biased, precisely by the fact of being appointed by one party. Numerous respondents suggest cross-examination as the most efficient and definitive solution to this problem of bias. Impartiality is almost not considered by the respondents, and the definition of independence does not get much attention either, except in reference to a party-appointed expert’s role—‘to offer ‘independent’ expertise that supports the party’. Most respondents also do not see a difference between these two concepts, akin to the judges. As noted above, cross-examination is highly recommended to identify potential expert biases and more generally to assess the ‘integrity of expert evidence’. It is also preferred over the new methods of oral interaction such as the ‘expert teaming method’. Opinions are divided on the development of rules or guidelines for greater precision in this procedure, though a majority is satisfied with the status quo. The relative legal uncertainty for the parties resulting from the absence of guidance regarding this aspect of the oral proceedings is somehow perceived as unproblematic by most of the respondents. The authors note that some procedural decisions in the past have been made ‘on the spot’ by the President of the Court18 seemingly relying on some unspoken rules, in accordance with the wide-ranging guiding principles of oral procedure in common law.19 All counsel interviewed agree with the suggested reduction in quantity of scientific/technical evidence submitted to the judge. Moreover, they all consider it advisable or a least possible, to receive more guidance from the bench, as to the expected content of expert reports. Finally, in contrast with the judges interviewed, respondents in this category are unanimous on the dubious nature of the practice of using phantom experts. In this sense, according to the counsel, the requirement of transparency clearly appears to be the common thread and one of the more important characteristics of the expert process. C. ICJ Experts The respondents in this category bring with them varied experiences, be it in their capacity of intervention (as counsel or expert witness) or their field of expertise. Despite this diversity of involvement and backgrounds, experts display more unified perspectives and opinions than the lawyers consulted. Experts are quite clear and in agreement regarding the definition of their role in the procedure when appointed by a party. This role is to enlighten the judge, on the party’s behalf, on technical issues within their areas of expertise, using words and in a manner intelligible to a lawyer. This is opposed to the opinions of the judges and counsel interviewed, who envisage this expert’s role as supporting the party. They emphasize that maintaining ‘professional independence’, ‘professional integrity’ and honesty is inherently important to them, and not merely because the weight of evidence provided by an expert deemed to be partial would be diminished. Related to issues of independence and impartiality, experts find a difference between ‘advocating’ and ‘expounding on the correct understanding of’ science, favourable to the appointing party. This is significant for understanding what ‘independence’ means for experts. To elaborate, as long as the experts are stating what they believe to be true and are not being dishonest to support the party appointing them, they consider themselves independent. In their opinion, even selecting, in favour of the appointing party, among more than one justifiable scientific opinion, an expert remains independent, if the opinion expressed is scientifically reliable. The experts interviewed do not consider that this selection affects the impartiality of an expert either (this word seems to be used as a synonym for independence). Independence is maintained even if the expert meets with the legal team, as long as it is to discuss specific scientific issues, and the expert does not know the legal strategy until the oral hearings. However, respondents also mention that parties made them understand the legal issues involved, and the legal significance of technical terms in dispute. Another respondent speaks of frequent collaboration with the party’s legal team. The absence of personal link between the expert and appointing party is not considered relevant for establishing independence. The use of ‘independence’, ‘impartiality’ and ‘honesty’ interchangeably by the authors in this paragraph reflects the frequent substitutions that the respondents made, among these terms, leading to difficulty in understanding what is precisely meant by each of them. As the interview respondents explain, experts that appear as witnesses are trained by the legal team for cross-examination.20 Respondents are all in favour of cross-examination remaining an integral aspect of expert procedures, since it helps in exposing the real issues in dispute. However, this is not to say that cross-examination is a straight path to easy resolution of scientific issues. Since opposing parties may produce experts to give opinions on different issues, without any guidance from the Court as to the area of expertise or issues to cover, the judges may ultimately be provided with one-sided data or evidence on several issues. The responding experts do not believe that the judges alone can assess conflicting scientific evidence to adjudicate on scientific issues. At the same time, absent clear definitions of independence, impartiality, there does not seem to be any clear parameters for judging the credibility, expertise or competence of an expert appearing before the Court. The respondents strongly favour appointment of an expert by the Court, if only as a ‘third voice’, to review the work of party-appointed experts. This preference derives, inter alia, from the absence of clarity and technical errors21 in past decisions of the Court. The prevalent opinion is that the Court cannot, by itself, properly understand and assess the quality and veracity of technical evidence provided by the parties. The ‘third voice’ would therefore assist the Court in understanding, assessing and clarifying the complicated aspects of this evidence, review the draft judgment. They should not conduct their own research, and not decide on behalf of the Court. However, it should be noted that even though the ex-curia expert is de jure strictly neutral, she would also inadvertently bring to bear her own background and prejudices into her assessment and may never be truly impartial—this is common with the views of the counsel interviewed, as well as some judges. To different extents, collaboration between opposing parties’ experts is favoured, since they help in narrowing the points of disagreement, which is helpful for the judges. The prevailing opinion is also in favour of new techniques and procedures22 developed in other spheres of international dispute settlement, not yet used by the ICJ, which also have the same effect of narrowing down the issues in dispute. D. Combined Outlook on ICJ responses The first conclusion from the overall responses related to the ICJ would be the possible utility of establishing a common theoretical framework of the expert before the Court. Indeed, the respondents display a great variety of opinions, exhibit profound disagreements and above all, adopt different perspectives and grids of analysis. However, they also share common concerns and there is agreement on certain points, among all respondents (Section i). On this basis, it is also possible to identify differences among the three categories of respondents, displaying divergences in opinion that may reflect the roles they play in the judicial system (Section ii). (i) Shared concerns and agreement on aspects of the use of experts among all respondents From an aggregation of the answers, beyond the disagreements there emerge common features in the answers as well as a certain pattern of understanding on several aspects: such as the ethical obligations of experts, the potential use for a ‘third voice’, concern regarding the delegation of the judicial function, the utility of collaboration between parties’ experts and need for the reduction in quantity of expert evidence submitted. The first common feature is the lack of clear definition of terms such as independence and impartiality, and the lack of clear conception of the role played by the different kinds of experts. Along with ‘independence’, the respondents often use terms like ‘neutrality’ and ‘honesty’, while impartiality is hardly, if ever, brought up. The axiological dimension of these terms fits the rather undetermined definition of the expert’s role. Moreover, the ambiguity in expected qualities of an expert arguably ultimately undermines the value of the expert opinion. That being said, assuring the effective independence of the expert was revealed by consensus to be a concern. Some respondents consider feasible the disclosure of the expert’s terms of reference and contacts with counsel of the parties, to allay doubts regarding his independence. Practice is varied, but in some cases the expert meets with the team, assisting it in framing the arguments in the case. The authors thus inferred that this assistance does not imply the betrayal of the expert’s convictions or his/her scientific standards. As the experts’ responses reveal, the expert often presents the various possible options to a problem, and in cooperation with the party, then supports the option most favourable to the party. Interestingly, this is not perceived to demonstrate a lack of independence or even partiality. The responses also reveal common concerns regarding the involvement of the ex-curia expert in the judicial process. The fear of delegation of a part of the judicial function is expressed, as well as apprehensions regarding the absence of an adversarial aspect in the process. Questions also arise regarding the burden of proof and equality between the parties. The judge, by appointing an expert, would somehow interfere with the normal allocation of the burden of proof and de facto favour the party invoking the fact in issue. These concerns seem to point towards the reasons for limited use of the ex-curia expert in practice. While reservations were expressed regarding ex-curia experts, the utility of a ‘third voice’ arose from the responses, to decide between competing scientific arguments. All kinds of interviewees contemplate this possibility to different extents. The experts considered it more of a necessity, all expressing concern as to the capacity of the judge, trained in the law, to effectively assess the different expert reports and presentations resulting from cross-examination. It is a common opinion that in some cases the adjudicator could need some additional information to properly assess and weigh the expert evidence. In that respect the Kishenganga23 case has been cited as example, illustrating the opportunity for lawyers to rely on the advice of scientists to correctly understand expert evidence. Respondents also agreed on the importance of reducing the quantity of expert evidence. This could be achieved by the judge using his capacity to provide guidance as to the content of the experts’ reports, both with respect to the substantive issues addressed and the form of the report. Respondents welcome collaboration between experts to ease the judge’s workload. The means that they consider, tend towards the following objectives: identification of methods, comparison, and identification of the points of agreement and disagreement. Different techniques can be used to achieve this goal, before and during oral proceedings: such as pre-hearing conferences and joint reports. Unfamiliarity with these procedures is perceptible in the responses, though the degree of acquaintance may vary among the individuals. However, even when associated with some practical difficulties, the idea of exchanges between the experts before the oral proceedings is considered valuable. Added to that, from a more theoretical perspective, this method is in line with the understanding that the role of the experts, even if presented by parties with opposing positions and arguments, is to help the judge by exhibiting their specialized knowledge. (ii) Opposing views among categories of respondents A marked diversity of opinions could be found among judges, counsels and experts on the efficacy of cross-examination, on phantom experts and the importance of transparency in that context. As asserted by most judges and counsel interviewed, cross-examination is the best means possible to arrive at an approximation of the ‘truth’. This technique, according to the responses, would allow judges to overcome every kind of bias (conscious or unconscious) or inaccuracy affecting expert evidence. It is the best means of revealing the inherent scientific quality of the expert’s opinion and independence at the same time. The trust in this technique is such that it can supplant the different safeguards and legal techniques that have been implemented in common law countries24 but are absent in the Court’s judicial practice. The responses from the experts, however, reveal a concern about the capacity (or incapacity) of an assembly of lawyers to effectively understand, in a scientifically sound way, the relevance and merit of a scientific approach, even if obtained after cross-examination. Several examples illustrated errors in past decisions, resulting from an inadequate assessment of the expert evidence.25 Thus although the experts agree on that cross-examination is essential, they do not perceive it as a sufficient procedure to efficiently make use of expert knowledge in a scientific dispute. Even if there is no direct opposition of views on transparency, counsel and experts place special emphasis on this procedural requirement. The responses of the judges do not reflect the same concern. Equal treatment of the parties is the component of transparency that seems to be the major concern. Counsel and experts repeatedly and clearly emphasize as being of utmost importance, the translation of this ideal into practice. They consider it necessary for the legitimacy of the decision to make the judicial reasoning clearly visible in the judgment. A related issue concerns the use of experts by the Court without the knowledge of parties (phantom experts). As mentioned earlier, experts and counsel have unequivocally manifested their disapproval of this practice, whatever the nature of the involvement of this ‘unseen’ expert. According to them, no exception to this should be permitted. Judges do not support this practice either, but with some important exceptions as discussed in Section II(A). Permitting such an individual to provide an unchallenged opinion to the Court, according to some respondents, could violate requirements of transparency and due process, as well as affect implementation of the decision. 3. INTERNATIONAL TRIBUNAL FOR THE LAW OF THE SEA This section delves into the insights gained from an analysis of the responses received from the various individuals involved with disputes before the International Tribunal for the Law of the Sea—some former and present judges of the Tribunal and its registry (Section A), counsel who have appeared or appear before the ITLOS (Section B), and only one expert that the research team was able to interview from this forum (Section C). A. ITLOS Judges and Registry Some varied responses are to be found from these respondents, and clear profiles appear throughout the answers. Different answers were provided concerning important theoretical concepts (role of the expert, role of the judge, capacity of dealing with scientific evidence) but these discrepancies, interestingly enough, do not produce any noticeable shifts regarding practical answers. None of the respondents advocate changes in the system. No clear reform has been suggested as to the text or to the practice, even by one respondent who at the outset in his responses states that the Tribunal is not well-equipped to deal with scientific issues. These respondents display a general satisfaction as to the functioning of the system and do not identify any evident problem that needs to be addressed. Some important points in common can be identified with the responses from the ICJ.26 An appreciable number of conclusions arising from the analysis of these interviews are in fact identical to the ones from the ICJ. First, all the respondents seem to share the assumption that the party-appointed expert is to be considered the norm for assessing scientific or technical issues, since it is self-sufficient and demonstrably efficient. Ex-curia experts may be used, in addition to the aforementioned, under certain circumstances. It has been considered, at best, as a theoretical possibility. As to the role of the expert, the answers are characterized by their lack of clarity (with the notable exception of one respondent) and their disregard for the concept of impartiality. One respondent makes clear, at least in his first answer, that an expert should have the same role, irrespective of the appointing entity. His comment is at a theoretical level. The remaining respondents used exactly the same reasoning as found with the ICJ respondents, considering the expert as an advisor of the appointing party even though constrained by the ethical and other obligations imposed on every scientist with professional integrity. As with the ICJ questionnaire, the parallel with the functions of an advocate is striking. According to the responses, like an advocate, the expert has to make the case for the appointing party but within the bounds of professional rules. The respondents consider the expert a part of the legal team and participating as a counsel before the Tribunal as a legitimate and valid possibility. This is why the wording to be found in answers of both ICJ and ITLOS responses is identical: ‘honesty’ and ‘scientific integrity.’ These terms are broad enough to encompass the attributes necessary to achieve a seemingly impossible balance between independence and deliberate support. As a result, only one respondent contemplates the possibility of implementing a code of conduct. Regarding the means at the Tribunal’s disposal to assess this elusive independence, he is the only one to mention the ‘voir dire’ process. This is a process used for testing the independence of an expert witness in US courts, unusual for an international tribunal.27 Used before the examination of a witness begins, for testing his/her eligibility, this process is distinct from cross-examination. Thus, the party conducting the voir dire is not permitted to question the witness on the subject matter of the issues involved. In the single ITLOS case where this was used, the President of ITLOS, drawing a distinction between the expert’s independence and thus suitability as a witness, and his capacity and expertise, clarified that the question of whether the expert is capable of providing scientific evidence, is part of the evidence itself, and not a component of voir dire.28 It is not surprising that only one respondent mentioned this procedure, since it has so far been used only once at ITLOS, even when an occasion later arose in the Malaysia v Singapore dispute29 where the impartiality of a testifying expert was clearly in question. The other interview respondents rely completely and solely on cross-examination to reveal any kind of bias (and scientific inaccuracy) that could affect the expert testimony. It is a unanimous opinion that cross-examination is of paramount importance and efficiency. When asked about the role of the ex-curia expert, respondents discuss the support provided to the judge in assessing the expert evidence submitted by the parties. Yet, one respondent develops on the necessity to educate the parties as to the role of the ex-curia expert, which does not involve per se any delegation of the judicial function. The respondents are divided regarding the utility of techniques that would foster collaboration between party-appointed experts. Differing from the judges of the ICJ, some respondents from the ITLOS are open to the possibility of using techniques such as expert conferencing or pre-hearing conferences, with the agreement of parties. It is also noted that the ITLOS Rules provide sufficient flexibility ‘for developing guidelines in this field’. The use of experts by the Tribunal results from the particular way it handles science. The regime of the expert before ITLOS can hardly be understood in isolation from the broader issue of the status of science in the law of the sea (as conceived by the Tribunal). As one respondent states: ‘in light of ITLOS approach ‘scientific uncertainty’ consists in conflict[ing] scientific evidence b[y] equally reliable scientific experts.” In this type of case, the judges will then draw inferences from this uncertainty and will not have to adjudicate between two competing scientific arguments presented by the party-appointed experts. That is another conceivable reason why the Tribunal did not find it necessary so far to appoint its own experts or make use of assessors as provided by Article 289 of UNCLOS. The Tribunal, confronted with scientific uncertainty, relies on a ‘precautionary reasoning’, that has direct influence on the integration of scientific evidence in the judgment and on the type of expert evidence required. These approaches make it all the more difficult to grasp the expert regime before ITLOS, because it is directly linked to the substantive legal issues. The examination of the responses also indicates the existence of phantom experts at the Tribunal. The respondents mention a category of experts which may coincide with the definition of phantom expert. While the Tribunal never made use of the possibility provided by Article 289 to appoint ‘expert-assessors’, it is interesting to note that some experts, according to all respondents, are working with the registry (not officially appointed). They help the registry in assessing scientific evidence and help in redacting the judgment [sic]. We could wonder why in these circumstances (where there is an apparent necessity of external technical help), the Tribunal disregards Article 289 of UNCLOS. One response suggests that it is the excessive proximity (in status and qualification) between these experts and the judges, which somehow makes them refrain from soliciting the support of these individuals. The presence of unofficially appointed experts and the non-use of article 289 remains nevertheless intriguing. On the question of appointing an expert after the completion of the written and oral proceedings, one respondent shelters behind his duty of confidentiality. Others confirm this possible use of the registry. This practice raises questions both about the role of these experts and the role of the registry in that respect. While the issue of phantom experts has been discussed in the context of the ICJ registry,30 the same concerns apply to the ITLOS. Albeit improving efficiency in clarifying issues of minor importance, it can be considered that this opaque process disregards the parties’ right to comment, an important facet of the sound administration of justice, which is thereby undermined.31 B. ITLOS Counsel Responses from this category overlap to a great extent with those of the ICJ counsel, not least because the individuals themselves overlap to a great extent with counsel at the ICJ. Yet, it is useful to highlight some key opinions of these respondents. Each of the individuals interviewed demonstrate varying approaches towards the use of experts. Like ICJ counsel, it was difficult to identify too many points of agreement, or even a few points of disagreement, to find the different threads of opinions on any aspect. Akin to the judges of the ITLOS and the ICJ counterparts, these respondents too consider the role of the party’s expert to be that of an advisor or advocate, and there is a natural presumption that such an expert is biased. As one respondent puts it rather paradoxically, the role is to “offer ‘independent’ expertise that supports that party”. Notwithstanding the above example, if one were to examine all the responses of these counsel as a whole, ‘independence’ as a term is hardly used to describe experts, neither is ‘impartiality’. ‘Honesty’ is used more liberally, along with ‘credibility’. It is not possible to gain a precise understanding of these terms however, from the contexts of the responses. Thus, eventually, we are left with an abstract understanding of the ethical obligations of experts. Cross-examination is unanimously considered very important, in fact the most efficient means of exposing weaknesses in the expert’s report and opinions. One respondent finds it a ‘better way to secure and test the integrity of expert evidence’ than drafting a code of conduct. Cross-examination is even preferred to the newer oral procedures such as expert conferencing, though that might be due to their lack of familiarity with these procedures, as revealed in the responses. When asked about the absence of a precise procedural framework governing cross-examination, some respondents are not in favour of more rules in this context, since it involves non-lawyers. A contrary opinion is that rules should be developed so that cross-examination is less ad hoc. There is also a minority opinion against the cross-examination of experts altogether. According to this interviewee, experts are usually well-prepared by counsel, thus nothing of significance is to be gleaned from questioning them. In other words, their lack of independence and impartiality renders cross-examination futile. Finally, the approach to phantom experts is also akin to that of ICJ counsel. The lack of a well-defined approach towards expert evidence and the consequent freedom of the adjudicator is, in the words of one respondent, “especially problematic if the Court relies on a ‘phantom’ expert unknown to the parties, whose views are not subject to scrutiny by them”. The primary concern expressed is that parties should be able to ‘raise issues concerning the skill and the independence of the expert appointed’. One respondent prefers that the tribunal, rather than the parties, appoint experts, but only if done ‘openly and transparently’. C. ITLOS Expert The sole expert interviewed with experience at the ITLOS, does not find much difference between working with parties and judges. In an important respect, her answers are very similar to those of the other experts before other international courts or tribunals. She considers herself as part of the team, and for her, being appointed by a party entails supporting the party’s claim. Only a court-appointed expert is expected to be independent. At the same time, the expert balances the duty towards the appointing party with honesty on technical matters. Similar to the ITLOS judges interviewed, the responses of this expert regarding her role support the belief that the expert is an advisor of the appointing party even though constrained by the ethical and other obligations imposed on every scientist with professional integrity. It is the role of a party-appointed expert to support the contentions of ‘his/her party’. Like the other interviewed experts, she raises an important criticism of the efficiency of cross-examination, stating that this practice can lead to some misunderstandings and misleading simplifications. Along with her colleagues who appeared before the ICJ, she warmly welcomed any proposal for working in conjunction with the expert of the other party. Therefore, she is also open to participating in pre-hearing conferences or expert conferencing, which she thought ‘has a number of benefits’. This expert’s overall impression of the expert process at the ITLOS is that it worked well in her experience. She placed the greatest emphasis on the ‘credibility’ of the expert: ‘it is essential that any technical expert has a strong international profile and credibility’. The term ‘credibility’, however, remains undefined. 4. INVESTMENT ARBITRATION The analysis of responses in this section is in two parts: the first, due to the special circumstances in investment arbitration is an analysis of responses from both arbitrators and counsel, the same individuals often donning both hats (Section A). The second part, similar to (Section C), analyses the responses of the single expert interviewed with extensive experience appearing in arbitration disputes (Section B). A. Investment Arbitrators and Counsel This subsection first provides a description of the responses of investment arbitrators and counsel (i), and is followed by an analysis of these same responses in a general context (ii). (i) Synopsis of key features in the responses With regard to the definition of the role of experts, whether appointed by the arbitrator or by the parties, there is the pervasive perception of similarity between the two, a duty being owed to the adjudicator in both cases. The few differences expressed in the answers rely on the practical consideration of implementation, but there is overall consensus on the principle that the general function of these experts is identical: providing well-reasoned independent and impartial opinion. Nevertheless, some respondents seem to consider in a somewhat contradictory manner, that the party-appointed expert also has to independently support the appointing party’s contention, finding ‘non-legal advocacy admissible’. Respondents generally agree with the assumption that the use of ex-curia experts is not an option that should be considered prima facie, when confronted with a technical case but should result from insufficiency or difficulties with the expert evidence presented by parties. It should generally remain exceptional and be performed after consultation with parties. Its function should not necessarily be limited to reviewing the expert evidence of the parties, and the answer depends on the particulars of a case. Nevertheless, the principle remains that the expert reports of the parties constitute the primary material. A majority of the respondents see the overdue influence of an ex-curia expert on the adjudicator’s findings as a legitimate issue, but believe that it could be tackled by adopting transparency measures and increasing involvement of the parties. Independence and impartiality were mentioned by all respondents as attributes every expert should possess. However, there is sometimes confusion between and conflation of the two notions, broadly defined in economic terms, such as a shared financial interest with a disputing party. Other respondents articulated the definitions very clearly and considered their legal consequences. To them, independence could be described as having objective links with the party, whereas impartiality refers to a state of mind. Generally, the same requirements should be applied to both types of experts. For some, in opposition to their theoretical understanding of the role of experts, a higher standard is expected from ex-curia experts in practice, one respondent stating that a party-appointed expert cannot be impartial. The assessment of independence and impartiality does not appear to be an admissibility issue, but rather a question of weighing evidence. Disclosure of the instructions is considered very useful or even necessary and already constitutes best practice. A respondent specified that disclosure of oral instruction could be useful, but difficult both in practice and legally (as privileged communication). The importance of oral examination of experts who have submitted a written testimony, ranges from important to indispensable. Cross-examination works without a precise procedural framework because according to the respondents, it is important to maintain flexibility in the process, and operates efficiently with common experience and background in arbitral culture of the counsel, arbitrators and other such participants in the arbitration. Respondents consider that judges should be proactive in managing the evidence, through different techniques (ordering joint report of party-appointed experts, ex-curia expert reports, experts commenting on each other’s reports or considering specific issues), but not at the outset of the proceedings. Narrowing down the issues dealt with by experts is deemed a good principle, for example with joint reports, but the decision to conduct the discussions, and the opportune time for these discussions should not be left to the appraisal of the experts. The effectiveness of the process would depend on the extent to which experts properly engage with each other in a bona fide, impartial way, without interferences from counsel. The assessment of the effectiveness and utility of the ‘expert teaming’ technique, is diverse, ranging from helpful to useless. More generally, only some respondents found an increase in the use of new methods in international arbitration even if most of them considered them useful. Concerning the management of evidence, the respondents seem reluctant to accept a strict understanding of the actori incumbit probatio rule, a rule that requires the arbitrator, when unable to effectively assess the parties’ evidence, to adjudicate in favour of the defendant. The practice of using internal expertise is considered inappropriate, and possibly at odds with due process requirements. It is however seen as possible in very exceptional cases such as practical implementation of legal conclusions, in boundary cases, for instance. Some respondents do not see this involvement as problematic since the expert is not participating in the deliberations or providing new evidence (again referred to as assessors). Mention was also made of the possibility for the adjudicator to appoint an assessor, an entity which is not used in international arbitration. The possibility of formulating and applying a code of conduct is considered generally helpful, but respondents consider that it should remain in the form of general guidelines, rather than a detailed code. (ii) Analysis of responses in general The answers provided were characterized by two main features: the technical and detailed nature of many responses on the one hand, and the circumstantial character of these answers on the other, reflecting the inherent flexibility of the arbitral procedure. Some distinct trends can be seen in these responses. Some respondents appear to have given much thought to the problematic of experts in international adjudication and seem very well-informed. This is not to say that there are unanimous opinions, in fact those are rare. However, the opinions are detailed enough (in many cases) to show the existence of a debate. Indeed, the answers seem to be generally informed by extensive practical experience. A more theoretical level of thought if present, is not merely in the abstract, because it relies on examples and precisely described legal institutions. Some respondents provide case-law in support of their arguments and discuss provisions from different bodies of arbitration rules. In the arbitration field, the familiarity with the expert and related legal institutions make the differences of opinion between these respondents less explicit and minimizes the importance of legal culture or professional background. While this common base does not preclude clear-cut oppositions and dissimilar perceptions or opinions, the perspectives adopted are not completely unrelated and permit avoidance of parallel discourses, a phenomenon observed with some of the respondents to the ICJ questionnaire. The importance of flexibility is emphasized throughout the questionnaire, respondents regularly highlighting the importance of adapting the expert process to the nature of the case. The respondents take care not to be dogmatic in their answers, and barely express themselves in terms of absolute solutions. One respondent even states in response to most questions, almost systematically, that his answer depends on the specifics of each case. The result of the conjunction of these two trends is the pragmatic approach prevailing in international arbitration. Consequently, the possibility of using ex-curia experts is contemplated, and there is no systematic disregard for the use of some inquisitorial methods by the arbitrator. There is no ‘claimed’ fundamental opposition between a common law approach and techniques in line with the civil law tradition. Generally speaking, the proactive attitude of the arbitrator in managing the evidence is seen as very advisable. However, the point of view adopted could be perceived as somehow originating in common law, as the role of the expert appointed by the tribunal is merely understood as revising parties’ expert reports or enlightening the tribunal on the evidence submitted by the parties, and not to proceed to its investigation which will base the adjudicator findings. In addition, the comprehensive involvement of the parties in an adversarial fashion into the work of the ex-curia expert appears to be unknown. The pragmatic approach is also reflected in the perception of the burden of proof, seemingly driven by no clear established principles. The handling of the allocation of the burden is rather determined by the nature and quality of the facts, the evidence contemplated and the circumstantial perception of the adjudicator. In this regard, there remains an uncertainty regarding the kind of justice (inquisitorial or adversarial) towards which the international arbitration process is leaning. Another distinctive feature in international arbitration appears to be the importance of the ‘individual’ factor. The personality of the actors and their behaviour are elements taken into consideration with respect to the relevance of a certain procedure, along with a strong implication of the trust vested in the somewhat closed community of players in international arbitration. Indeed, several responses referred to the good will of the judicial actors as well as their knowledge of the procedure or their sincerity in commitment to a common work. Also of particular note is the lack of clear answers regarding the question of admissibility of expert evidence. It seems that lack of independence of an expert is more a question of the weight to be given to evidence than admissibility. The lack of intelligibility in the answers for such a question is surprising, considering the importance of the procedural consequences conveyed by the choice between the two alternatives. A similar conclusion can be drawn for the definitions of independence and impartiality of the expert. Responses are at least dissimilar, some of them even being in clear opposition. For example, the ‘expert-counsel’ performing non-legal advocacy is seen by different respondents as either unacceptable or conversely, appropriate. Finally, the practical approach in arbitration seems to, on some occasions, impede a systemic understanding of some broader concepts, such as the judicial function, which varies depending on the specificities of the case considered. Indeed, the casuistic methodology adopted towards procedural problematics, and the sui generis solutions generally advocated by the respondents, make unclear for instance the principles driving the allocation of powers between the judge and parties as to fact-finding. As mentioned earlier, the inquisitorial or adversarial character of the procedure (a question directly related to the adjudicator’s function) seems to be varying according to the particular circumstances of the case. B. Investment Arbitration Expert As with ITLOS, this subsection focusses on the views expressed by one expert with extensive experience in the arbitration field. This expert appeared before major arbitral institutions such as ICSID, ICC, LCIA, Iran–US Claims or several Panels of Commissioners at the UNCC. He shared his thoughts about his experiences as expert appointed by both tribunal and parties. According to the respondent, with regard to the different functions of experts, the party-appointed expert has to ‘support the opinion evidence in such a way as to facilitate the tribunal’s finding on the debated technical question’. When the expert is appointed by the tribunal, his/her role is to ‘translate the technical reports and opinions of the party-appointed experts so as to facilitate understanding’ by the tribunal members. The respondent made clear that be it for the ex-curia expert or the party-appointed expert, the overriding obligation is to the tribunal. In other words, the function of an expert is to provide help to the adjudicator in understanding complex facts or evidence. The respondent identified independence and impartiality as fundamental requirements to acting as an expert, whatever the capacity in which he/she is involved in the procedure. He distinguished between these two qualities by considering that independence manifests itself when a party-appointed expert acts with freedom and in the absence of control by the party. In contrast, an expert acts impartially by acting without bias in favour of the client. The respondent explained that the opposition between experts’ views resulting from different methodological approaches constitutes a common problem hindering the adjudicator’s appraisal of the evidence. In this respect, the respondent expressed support for different techniques aiming to ‘coordinate’ the work of the party-appointed experts. He generally considered it useful to enter into discussion with the expert of the other party to identify respective objectives and methods. In that respect the preparation of a joint report is deemed ‘very useful’ and pre-hearing conferences ‘almost always do help’. The witness conferencing technique is seen as potentially helpful, on the condition that it be ‘controlled and managed firmly by the tribunal’. In any case, the respondent explained that in procedural mechanisms related to experts, a subjective element should be taken into consideration, their efficiency depending upon the attributes and objectives of the individuals involved in the process. He considered cross-examination helpful but contingent on the attitude, objectives and cross-examining skills of both lawyer and expert witness. 5. WTO This section provides an analytical assessment of the responses received from panellists and members of the Appellate Body of the WTO (Section A), counsel who regularly appear or appeared before WTO panels (Section B) and members of the WTO Secretariat (Section C). A. WTO Adjudicators The responses here come from a variety of individuals, though all are or have been adjudicators in the WTO Dispute Settlement System (DSS). Some are current or former members of the Appellate Body (which does not engage in fact-finding), some have been panellists. There is unanimity regarding the premise that existing rules are well-equipped to deal with technical and scientific data (with minor disagreement on the reasons for the same), and that absence of precise and rigid guidance in the covered agreements is an advantage. The resulting flexibility would allow panels to decide how best to use their consultation with experts. It is commonly admitted that practice has developed ‘reasonable procedures’ at the WTO. However, despite overall satisfaction with the system, one opinion is that that the texts are not necessarily as effective as desirable inter alia because of: the multiplication of detailed expert reports (rendering their assessment very difficult), the inequality of arms (unequal access to experts between parties and panel), absence of effective cross-examination or infrequent appointment of experts by panels. All respondents also mentioned the specificity of the WTO DSS entailed by its quasi-judicial nature. According to some respondents, comparison with any other international bodies will not help to shed light on WTO dispute settlement procedures since the Dispute Settlement Understanding (DSU) represents the outcome of negotiation and agreement among all the Members. Due to this specificity, the DSS would likely not be influenced by the practice of other unrelated bodies. For some respondents, the category of the ‘party’s expert’ exists de facto. Within a delegation there may well be an ‘expert’ defined as such. Besides being an ‘internal’ advisor to the party employing it, an expert may be called to give evidence (submit a report) on behalf of that party and therefore perform an official role. One respondent in consequence strongly prefers modifying the legal texts to use experts as witnesses, thus formalizing cross-examination as well. For other respondents, conferring legal status on this category would not be useful, and it would add a layer of unnecessary complexity to the system. A respondent explained that the panel is not required to pass a judgement on the science applied but rather on the reasonability of the trade measure imposed to reduce the risk posed to health, etc. Therefore, it needs only to have enough understanding to perform its function, which apparently excludes the necessity of a detailed system of expert evidence. The consulted adjudicators were unanimous in the opinion that party-appointed experts were hired to provide the information that would support the case of the appointing party and are ‘expected to be biased’. According to the same, they are neither required nor expected to be independent from the appointing party, nor impartial. The respondents mentioned however that party-appointed experts have a certain duty of objectivity and truth based on their profession’s rules of conduct. With regard to the attributes of a party-appointed expert and its functions, respondents presented complex answers and created intricate balances between support without impartiality and, at the same time, objectivity. In contrast, the expert appointed by a panel is invariably considered as independent and impartial. Even if the definitions of these two concepts vary, a difference is generally acknowledged between them. It is agreed upon that the function of an ex-curia expert is helping the decision-maker by offering scientific information and assessment to the panel on questions that it considers relevant to the case. By doing so, it helps the panel to become better acquainted with the technical or scientific intricacies behind the arguments; to understand the logic, and thus the bias, behind the arguments of each party. Some respondents are of the opinion that de facto cross-examination takes place through questions from the parties, and by the panellists. For one respondent, conversely, there is no effective cross-examination. He explained that an expert answers questions by the panel only to the extent that the head of the delegation considers that the expert should be the one to answer a particular question. According to this opinion, this presents a problem since experts are entitled to express views on paper without an intrusive examination, and it becomes difficult to evaluate these parties’ expert reports. One respondent advocated that for the panel to get to the heart of the issue, more intrusive engagement is required, with increasing adversarial procedures, be it by cross-examination or hot-tubbing or other procedures. With regard to the factors a panel should consider in deciding whether a dispute requires expert appointment for proper adjudication, a variety of arguments were presented: nature of the dispute, views of parties, arguments of parties in first written submissions, complexity of expert evidence submitted by parties, assessment of available internal resources (secretariat), degree to which panellists feel comfortable with their ability to understand the scientific arguments that will be made to them, availability of experts, and impact on length of proceedings. Adjudicators were unanimous in considering that the selection process of ex-curia experts should remain flexible. They consider that the adversarial nature of this process should not be increased, parties should not be more involved in the selection process than they currently are. Concerning the introduction of a code of conduct for party-appointed experts, the opinions are divided. Some respondents consider a code not useful or not even a possibility. Such experts are the responsibility of the parties alone. Other respondents on the contrary considered this additional guidance a useful possibility. It is a popular opinion that, if panellists do not have professional backgrounds in economics backgrounds, or those with economics backgrounds are not sufficiently equipped for that particular case, the presence of in-house experts at the secretariat obviate the need for appointing experts. While economics is not immune from diversity and complexity, the capacity of the panel to understand and evaluate all those aspects would be far greater than on SPS or TBT issues, in which factual issues imply physical or biological sciences. One respondent, however, criticizes this approach when some of the economic issues are so specialized, that in-house expertise may not be good enough to truly understand those issues. B. WTO Counsel The overall approach to the WTO legal framework, of counsel interviewed, is uniform. There is general agreement on the minimal guidance concerning experts in the covered agreements, characterized by their broad scope and flexibility in this regard. Respondents do not agree however on the benefits of this system. According to the majority of interviewees a flexible approach going along with a vision of an ‘organic’ justice (opposed to a formally written or codified one), constitutes the appropriate framework for handling complex technical/scientific cases, relying mainly on practice. Panellists would have carried out the relevant changes in an evolving manner and ensured the implementation of these good procedural practices. However, another group of respondents consider that the WTO Dispute Settlement procedural rules do not lend themselves to an adequate examination of experts and facts in general. Looking at the practice, these respondents demonstrate that panels have not been taking advantage of this flexibility, and thus there is a need for more specific rules that require panels to take certain steps. They consider that panellists themselves, in general, do not have the capacity or the willingness to deal with factually complex cases often. The diplomatic nature of the DSS and its determinant influence on the expert regime was also mentioned by all the interviewees. Some respondents explained that the DSU was prepared by non-litigators, and was not designed to regulate a judicial system but to help resolve disputes and foster negotiations. A set of very precise rules, including evidence, would have been perceived for some reasons as favouring the wealthiest countries at the expense of the developing world. This perception, and the legal cultural differences among members would, according to some counsel, prevent any reform in this text, which represents the highest common base achievable between Member States. Counsel agree on the fact that practice saw the de facto creation of the party-appointed expert before the panel, even if no such category is mentioned in the DSU. Even if formally part of the delegation, they may be presented as experts and present expert evidence. Panels and the Appellate Body have acknowledged this mechanism by mentioning in several decisions the presence of experts during the proceedings and the produced expert evidence as an element on which they relied in their factual determination.32 A common thought among the counsel interviewed is that a party’s expert is inherently partial, having a role of advocating the position of its party, even if morally constrained by their professional ethical rules. Adjudicators have the same understanding of this role. A respondent advocated that the partiality of the expert should be maintained unless detrimentally obscuring the distinction with the panel-appointed expert. Respondents discussed as well, the de facto existence of a cross-examination process for experts. A panel has the possibility to ask questions to the party-appointed experts as well as the parties through it, by suggesting questions to the panellists. In the absence of any procedural guarantee as to the independence and competences of the expert, this questioning would allow assessment of the reliability of the presented evidence by weighing the credibility and knowledge of the expert. However, some of the respondents are of the opinion that in any case, would the panellists be active and the parties willing to test the experts, the procedure is not close to corresponding to an actual cross-examination. The parties are indeed, only allowed to suggest questions to the panel. With regard to practice, a few respondents noted that the proactive attitude of the panellists that should constitute the condition for an effective and balanced presentation of expert evidence, through their questioning, is deplorably absent. Panellists remain generally passive when confronted with ‘expert testimony’. Their non-professional status coupled with their usual lack of litigation experience would present a problem, impairing the system. Other respondents mentioned in addition, abuses with the parties’ conduct in relation to expert evidence. They tend to take advantage of this absence of engagement and submit the maximum expert reports possible to ‘have the last word’. Parties also tend to present some expert evidence as late as possible during the proceedings and they do not always present their experts during the hearings in this capacity. In addition, respondents explained that parties do not intend to question the other party’s expert during the hearing, having no certainty as to the answer that may be received. Some respondents argue that the actual functioning of the DSS does not reflect its adaptation capacity rendering the absence of a clear framework problematic. Some respondents recommend the adoption of a set of guidelines establishing agreed principles applicable to the evaluation of scientific/technical evidence. They also considered the possibility of adopting a code of conduct for experts.33 A counsel made the point that the regulatory autonomy of WTO members is independent of the evidentiary system adopted, procedurally speaking; or in other words, the regulatory autonomy does not require a weak system of evidence. According to him, a sound and fair establishment of the facts is a condition of the neutrality of WTO towards the political content of the challenged national measures. Others argued in the same direction that the absence of procedural tools and guidance given to the adjudicator to gather and assess factual elements is potentially problematic. The weakness of the evidentiary system tends to make correlatively more important the role of the secretariat in the assessment of evidence, which could theoretically be raising concerns of undue influence. Despite the fact that presenting an independent expert is in the interest of the parties, some rules should exist for testing this evidence, cross-examination being one of them. Satisfied by the translation of the flexibility in legal texts into practice, respondents unsurprisingly judge the implementation of a code of conduct as well as other procedural techniques such as pre-hearing conferences as counterproductive, or even unfeasible, like the expert teaming method. A respondent demonstrated that joint expert reports could pre-empt the adjudicative function. Formal cross-examination would represent a detrimental and useless delay. All respondents acknowledged that panels benefit from in-house expertise provided by the secretariat for questions concerning economics, and also mentioned the skills and dedication of its members. Some respondents however see the expertise of the secretariat in economics-related questions as potentially problematic, due to the opacity of this system that makes it impossible to know who is providing the advice to the panel and what type of knowledge is transmitted. The difference in treatment of scientific evidence (involved in SPS cases), justifying the appointment of an expert by the panel, has been criticized as well. C. WTO Secretariat Given the large number of members of the WTO secretariat consulted (as compared to the ICJ and ITLOS registries), a separate part has been dedicated to analysis of their responses. Respondents consider the relevant texts of the WTO well-equipped to deal efficiently with technical and scientific data in disputes before it. There is agreement on the fact that the legal instruments provide for a diversity of possible processes concerning experts and for the panel to seek information from any source. The existing rules are deemed sufficient by nature of their flexibility. Consequently, all respondents stressed that the corresponding practices developed have played and continue to play a very important role in improving the system. No call for reforms were specifically made but the practice and its evolution is stressed as an important element to provide improvements to the system. One clear opinion was expressed that no reform of the text is needed because of evolving practice with the guidance of the secretariat. This point of view implies that directions and choices are possible within the legal texts, and the ones made so far seem suitable. Some practice has indeed developed with respect to confidentiality, conflict of interest, role of the disputing parties in expert selection and questioning process. One opinion is that these practices deserve to be codified, albeit preserving the flexibility of the overall system. Although largely descriptive, the analysis provided by the respondents generally display implicitly a sense of satisfaction, because another mode of functioning appears inconceivable. The solutions adopted in the dispute settlement mechanism as to scientific cases and the expert regime seem to be stemming from pure logic and pragmatism. From the answers, the system seems immune from criticism and the expert regime taken for granted. The definitions of procedural terms and concepts are apparently forged through WTO practice and jurisprudence and established to accommodate the current functioning of this expert regime. For example, the possibility to ask questions during a hearing is seen as the exact equivalent of a cross-examination process, which is a rather restrictive concept of cross-examination. Indeed, the answers reflect that the use of the expert, in its concept and understanding is specifically framed and defined by and for the judicial environment in which it operates. In other words, one can sense that the mere definition and basic functioning principles of these classical institutions of judicial dispute settlement (such as expert evidence, cross-examination, impartiality) is shaped from a WTO perspective. Another consequence of this inside perspective and with the expert regime arising substantially from practice, is the apparent difficulty to understand or admit the utility of reform proposals based on principles and ideas, merely coming from mechanisms alien to WTO issues and specificities. According to some respondents, the experts effectively considered in the WTO context are only the experts appointed by panels. The DSU ignores witnesses and testimony and therefore experts presented by the parties, as well as the procedural techniques related to it. Adopting a strictly formalistic point of view, these respondents stated that there are just delegations and arguments presented by them to make their case. They do not distinguish between factual or legal argument or testimony or advocacy, attributing no specific nature in this context to the scientific knowledge. Other respondents however distinguished between two categories of experts: appointed by the panel and experts of the parties. For them, the party-appointed expert is a distinct actor in dispute settlement mechanism despite an absence of consideration in the relevant texts. The respective functions of the two types of actors are considered discrete, and thereby it is very useful to have both present in a procedure. The respondents generally considered that party-appointed experts are biased by definition and have a function of providing support to the arguments presented by the appointing party. Consequently, the opinion has been expressed that the introduction of the expert-witness or party appointed expert in the texts would require establishment of safeguards concerning, inter alia, conflicts of interest. Some respondents stated that concepts of independence and impartiality are even irrelevant in this context and cannot apply to the scientists that are members of the delegations and are mostly government officials who were in charge of formulating the scientific basis of the disputed measure. There is a disagreement with regard to cross-examination procedures for party-appointed experts, deriving logically from the different approaches towards the existence of this expert. The view has been expressed that de facto cross-examination occurs. In contrast, a group of respondents consider that cross-examination is not conceivable because there is no party-appointed expert but only delegations composed of a variety of individuals freely determined by the Member States. This informality resulting from the broad scope of the texts with regard to evidence is generally understood as a continuation of the diplomatic origin of the dispute settlement system under the former GATT. A similar view has been expressed by one respondent, detailing that the ‘cross-examination’ process does not fit the WTO DSU approach which is to find mutually acceptable solutions. Such a process will be unhelpful because adversarial approaches are not sought by the DSU. A group of respondents explained that scientists are usually included in the delegation only to answer potential technical questions of the panellists during the second hearing, and not to make an oral statement or a presentation. The inclusion of ‘experts’ during the hearings would not be intended to present an expert report or to assure that a cross-examination process has been conducted. Another respondent added that parties become increasingly reluctant to engage with each other by means of questions during the hearings, some members even refusing to answer the question of the other party. The same respondent explained that with the introduction of the figure of the party-appointed expert a formalized cross-examination procedure, seen as rather inconsistent with the general philosophy of the current system, would be opposed by the Member States. The view is unanimously shared that the panel-appointed expert is neutral and unlike the party’s expert she is advocating no specific position in relation to the dispute because she is bound by the same rules of conduct as the panellists. Flexibility in the mode of selecting experts is also stressed by all respondent as a crucial element. A respondent explained that a ‘general procedure’ to balance this flexibility could be useful to identify, to ensure uniformity and legal security for the parties. In general, additional guarantees, or a more precise framework for specific questions are admissible since the parties agree. All respondents acknowledged the in-house expertise in economic matters provided by the secretariat without a transparent framework, but this sort of expert involvement does not appear problematic to them in any manner. 6. CONCLUDING OBSERVATIONS: COMMON FEATURES AND TRANSVERSAL CONCERNS There is no unity of the expert regime in international law, if such a regime even exists in international law. The expert is an important actor in international disputes, but its existence and manner of functioning is not well-discernible through existing international legal rules. The questionnaire responses revealed a great diversity of opinions and conceptions, and almost every respondent presents specific personal analyses/traits. The legal cultural background of each respondent seems to play an important role in its understanding of the expert and procedural institutions surrounding its use. Although respondents did not necessarily advocate solutions drawn entirely from their legal system of origin, the appraisals of procedural elements are influenced by this legal cultural perspective. The professional record and the diversity of the litigating experiences appear to play a visible role as well. That being said, it would be wrong to assume a complete ‘scattering’ in the answers. It is still possible to identify common patterns and trends. Considering a specific court or tribunal, some common perceptions are to be found within the same category of interview respondents. The answers of experts are clearly distinguishable from the answers of the other actors. Counsel, even in complete opposition regarding the substance of eventual reforms, manifest, at least on some occasions, common concerns. Without exaggerated generalizations, and keeping in mind the specificity of the methodology of this qualitative study, adjudicators can be described as the most conservative or cautious group of respondents while counsel the most prone to advocating changes. In this regard, a specific mention should be made of the WTO secretariat which seemed to be the most satisfied among all categories of respondents with the current functioning of their system concerning experts. Finally, the most relevant perspective from which to analyse the expert regime is the forum. Common shared conceptions arise from the involvement before a specific court or tribunal. Indeed, the opinions, ideas, concepts and definitions presented, even if dealing with legal categories that appear universal such as witness or evidence, are based on the procedural mechanisms specific to the forum considered. In many cases the analysis displays an implicit sense of satisfaction with the system, because, to the respondents, no other mode of functioning seems feasible. On not rare occasions, it appears that the existing expert regime is taken for granted and is immune from criticism, because the definitions of procedural terms and concepts seem to be based on a specific forum, its practice and jurisprudence. These definitions are established to accommodate the way the expert regime operates at present, rather than the other way around. The suggestions for reform, especially when deriving from other forum practices, be it at the international or domestic level, are then difficult to integrate. Even if each analysis should be placed in context of its forum and not realized in abstracto, transversal concerns can be easily identified across the different international courts and tribunals. From all the answers there appears a lack of clear definition with regard to the role of each category of expert. The function of the party-appointed expert is almost constantly described as between advocating or entrusted with a supportive mission of the party hiring him/her and a kind of rather undefined intellectual independence. The expert certainly appears to be supporting a party, but in an independent manner. Even before WTO dispute settlement bodies, where the expert presented by a party is openly admitted to be partial, some ethical requirements are still expected from these actors. The combination of these two elements, support and honesty, is lacking clarity. A similar conclusion can be drawn for the ex-curia expert to a lesser extent. It is unanimously admitted that a court-appointed expert’s function, in terms of principles, is to provide help to the adjudicator in understanding complex issues, and therefore to be ‘neutral’. However, it is more difficult to find a common ground on his/her precise function: assessing facts, providing opinions on facts or clarifying evidence of the parties. It is also difficult to identify the legal nature of this input: is the expert providing evidence to the adjudicator on the evidence submitted by a party? Logically enough, as a consequence of the absence of clarity of the role, the definition of independence and impartiality is unsettled even when formally considered. The theoretical gap regarding the status of the expert, as discernible from legal instruments and the interview responses, results in what may be called a ‘procedural anthropocentrism’ in the understanding of the institution. The expert in fact, is understood as a single figure, without any real status of its own. Attention is focused on the person, considering her specific knowledge or skills or both. This is reflected in the variety of capacities in which she intervenes during a procedure. Thus, individuals with specialized scientific or technical knowledge, appearing as counsel, witnesses, assessors, adjudicators or informal advisors to the Court, formally remain experts in the perception of the interview respondents. The qualification ‘expert’ remains unchanged regardless of the mode of intervention. Therefore, what emerges from an overall assessment of the study, considering all responses as a whole, is the need for definitions. Notwithstanding the specificities of each forum, fundamental concepts such as role of an expert, independence, impartiality, burden of proof and standard of review are common to all kinds of dispute settlement. Agreement on the meaning of these common concepts would go a long way towards clarifying the expert regime in international law. Thereafter, keeping these common principles and common understandings of terms as a benchmark, specific reforms could be conceptualized, or evidentiary procedures streamlined, as required for each forum. While considering these reforms, it is important to keep in mind that the expert cannot exist in a vacuum. It needs to be thought of as part of a process, within a single framework, not separate from other actors involved in the judicial system. A way to efficiently conceive of the regime of the expert would be to think in terms of an ‘expert process’ which should be understood as a process of support to the decision-maker. The expert is then the personal component of a broader procedure whose function is to permit the introduction of factual complexity into the legal decision-making process. Such a definition would allow encompassing of all the different practices (such as ex-curia experts, party-appointed experts or assessors) and would consider this actor—the expert—within one comprehensive framework whose fundamentals and structural principles can be agreed upon. Irrespective of the legal tradition, some universal characteristics of the functions, qualities and mode of functioning of experts may be identified. The authors consider that these characteristics are primarily to be found in due process requirements. Indeed, the guarantees of fair trial can and should extend to any procedure. They also constitute the appropriate measure of a good expert process. This basis of assessment provides generic qualities that are difficult to challenge. Every expert process should be imbued with the following elements: transparency, adversarial character, independence, impartiality and equality of arms. The identification of certain qualitative criteria (both fundamental and consensual) is the means to reach a true critical assessment of the different existing practices, of the reforms proposals and of the legal institutions that can be envisaged. Though the sound application of the due process requirements may appear consensual at first sight, it could entail far-reaching consequences with regard to the expert regime and related procedural elements. For example, it would likely prohibit the use of invisible experts by a Tribunal. The jurisprudence of the European Court of Human Rights (ECHR) is valuable in that respect. In the Mantovanelli34 case, the ECHR stated that ‘as to the documents taken into consideration by the expert, the applicants only became aware of them once the report had been completed and transmitted. Mr and Mrs Mantovanelli were thus not able to comment effectively on the main piece of evidence. The proceedings were therefore not fair as required by Article 6 para. 1 of the Convention (art. 6-1). There has accordingly been a breach of that provision (art. 6-1)’. Following the Mantovanelli decision, it could be argued that the use of phantom experts infringe the right of due process within the meaning of article 6.1 of the European Convention of Human Rights.35 This approach to the expert process has been adopted by the European Expertise and Expert Institute in its Guide to Good Practices in Civil Judicial Expertise in the European Union,36 encompassing in a comprehensive fashion the practices of all Member States. In the same vein, the European Commission for the Efficiency of Justice37 in its 2014 report on European Judicial Systems38 made recommendations regarding practices governing judicial experts relevant to all legal systems that govern Member States of the Council of Europe. This comprehensive approach could provide conditions for a constructive dialogue between different opinions regarding experts, permitting effective grasping of opposing ideas and avoiding the possibility of parallel discourses relying on different perceptions and assumptions as displayed in the interview responses. Footnotes 1 ‘Experts and International Courts and Tribunals’, funded by the Swiss National Science Foundation, Project number 10001A_156117, Swiss National Science Foundation, 2015–2019. 2 The research design combines different studies and methods (theoretical and empirical). Currently, there exists no comprehensive study listing and analysing all the rules governing the use of experts before international courts and tribunals, and drawing comparisons between these different rules, nor their eventual historic development. 3 J Kirk and ML Miller, Reliability and Validity in Qualitative Research (Beverly Hills Sage Publications 1986) 9. 4 ibid. 5 L Webley, ‘Qualitative Approaches to Empirical Legal Research’ in Peter Cane and Herbert Kritzer (eds), Oxford Handbook of Empirical Legal Research (OUP 2010) 6. 6 ibid. 7 Described by Patton as ‘The logic and power of purposeful sampling lie in selecting information-rich cases for study in depth. Information-rich cases are those from which one can learn a great deal about issues of central importance to the purpose of the inquiry, thus the term purposeful sampling. Studying information-rich cases yields insights and in-depth understanding rather than empirical generalizations’: MQ Patton, Qualitative Research and Evaluation Methods (3rd edn, Sage 2002) 169. 8 ibid, see also on the topic, H Suri, ‘Purposeful Sampling in Qualitative Research Synthesis’ (2011) 11(2) Qual Res J 63. 9 ‘Will be representative in the sense of capturing the range of variation in a phenomenon, but not in the sense of allowing for the estimation of the distribution of the phenomenon in the population as a whole.’ 10 Relations with experts before the oral proceedings, during and after. 11 The interviews included questions on expert conferencing, hot-tubbing, expert teaming and single joint expert. For a discussion on these procedures, see MJ Hunter, ‘Expert Conferencing and New Methods’ in A J van den Berg (ed), International Arbitration 2006: Back to Basics? (Kluwer Law International 2007) vol 13. 12 Questions on this aspect were included in all questionnaires in the survey due to the absence of a unified understanding of the role of different kinds of experts, be they court-appointed, counsel-experts, expert witnesses or appearing in any other capacity. 13 M Moïse Mbengue, ‘Scientific Fact-Finding by International Courts and Tribunals’ 3 (2012) JIDS 509; D Peat, ‘The Use of Court-Appointed Experts By the International Court of Justice’ (2014) 84 BYBIL 271, 276; A Riddell, ‘Evidence, Fact-Finding, and Experts’ in CPR Romano, KJ Alter and Y Shany (eds), The Oxford Handbook of International Adjudication (OUP 2014); L Malintoppi, ‘Fact Finding and Evidence before the International Court of Justice (Notably in Scientific-Related Disputes)’ 7 (2016) JIDS 421, 435. 14 Corfu Channel Case (United Kingdom v Albania) (Merits, Judgment)  ICJ Rep 4. 15 In the Gulf of Maine case, the Court appointed an expert at the request of parties, provided in the compromis: Delimitation of the Maritime Boundary in the Gulf of Maine Area (Canada vUS) (Merits)  ICJ Rep 246, 253 (art II.3 of the compromis). 16 Maritime Delimitation in the Caribbean Sea and the Pacific Ocean (Costa Rica vNicaragua), Order of 31 May 2016  ICJ Rep 235. 17 or ‘phantom experts’. The term appears to have been coined by Judges Al-Khasawneh and Simma in a joint dissenting opinion: Pulp Mills on the River Uruguay (Argentina v Uruguay) (Judgment) (Joint Dis Op Al-Khasawneh and Simma),  ICJ Rep 108, 114; see also P Couvreur, ‘Le Règlement Juridictionnnel’ in Société Française Pour le Droit International (ed), Le Processus du Délimitation Maritime : Etude d’un cas Fictif—Colloque International Du Monaco du 27 au 29 Mars 2003 (Pedone, Paris 2004) 349. 18 See, eg, Elettronica Sicula S.p.A. (ELSI) (USA v Italy), (Judgment)  ICJ Rep 15; Application of the Convention on the Prevention and Punishment of the Crime of Genocide (Bosnia and Herzegovina v Serbia and Montenegro), (Judgment)  ICJ Rep 43; Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v Nicaragua) and Construction of a Road in Costa Rica along the San Juan River (Nicaragua v Costa Rica), (Judgment)  ICJ Rep 665. 19 HM Malek and others (eds), Phipson on Evidence (17th edn, Sweet and Maxwell 2010) 354, paras 12–11, 12–15. 20 This could raise the fear of a lack of independence and conflation with the role of counsel; however, it must be kept in mind that even fact witnesses, whose role is never confused with that of counsel, are trained for cross-examination. 21 See Land and Maritime Boundary between Cameroon and Nigeria (Cameroon v Nigeria: Equatorial Guinea intervening), (Judgment)  ICJ Rep 303. 22 Above (n 14). 23 Indus Waters Kishenganga Arbitration (Pakistan v India) (Final Award), 20 December 2013, <pcacases.com/web/sendAttach/48> accessed 7 February 2018. This case included on its 7-judge bench, Dr Howard S Wheater, FREng, an engineer, along with six other judges, trained in the law. 24 Such as pre-hearing conferences, expert conferencing and hot-tubbing. See UK Civil Procedure Rules (1998), Rule 35.12; Expert Evidence Practice Note (GPN-EXPT), Federal Court of Australia <www.fedcourt.gov.au/law-and-practice/practice-documents/practice-notes/gpn-expt> accessed 7 February 2018; US Federal Rules of Civil Procedure, Rules 16, 26. 25 See, eg, Cameroon v Nigeria (n 21). 26 On the common aspects and differences between the legal framework and practices of the two fora, see L Boisson de Chazournes and G Gros, ‘L’expert et le Tribunal international du droit de la mer’ in Les 20 ans du Tribunal international du droit de la mer (Pédone 2017) 185. 27 It was used only once at the ITLOS, in the Southern Bluefin Tuna cases between Australia and Japan: Public sitting held on Wednesday, 18 August 1999, at 10.00 a.m., at the International Tribunal for the Law of the Sea, Hamburg, President Thomas A Mensah presiding in the Southern Bluefin Tuna Cases (New Zealand v Japan; Australia v Japan) (Requests for Provisional Measures), Verbatim Record, ITLOS/PV.99/20/Rev.2, 34. 28 ibid 38. 29 Land Reclamation by Singapore in and around the Straits of Johor (Malaysia v Singapore), Provisional Measures, Order of 8 October 2003,  ITLOS Reports 10. 30 Above (Section 2). 31 CJ Tams, ‘Article 50’ in A Zimmerman and others (eds), The Statute of the International Court of Justice: A Commentary (OUP 2012) 1287 at 1298; Markus Benzing, ‘Evidentiary Issues’ in Zimmerman ibid 1234 at 1259. 32 See, eg, US—Subsidies on Upland Cotton, Report of the Panel (8 September 2004) WT/DS267/R; European Communities—Measures Affecting Trade in Large Civil Aircraft, Report of the Panel (30 June 2010) WT/DS316/R. 33 It should be noted that rules already apply to experts appointed by panels: Rules of conduct for the understanding on rules and procedures governing the settlement of disputes, WT/DSB/RC/1, (96-5267), 11 December 1996. These rules also apply to panellists; Appellate Body members, arbitrators and members of the secretariat. The governing principle (section II) is that ‘Each person covered by these Rules […] shall be independent and impartial, shall avoid direct or indirect conflicts of interest and shall respect the confidentiality of proceedings’. 34 European Court of Human Rights, Mantovanelli v France, Application no 21497/93, 18 March 1997. 35 See G Gros, ‘Unseen Actors as Unseen Experts: Ghosts in International Adjudication’ (forthcoming). 36 The foreword of the document specifies that the research intended to assess: ‘The various practices and experiences from very different systems, from common law and civil law, and to draw out the best of these practices in order to propose a common foundation to improve civil judicial expertise’. This guide, prepared with the financial support of the Directorate General Justice of the European Commission, results from research conducted for more than 10 years, bringing together a large community of judges, lawyers, judicial experts, academics and students of law: Guide to Good Practices in Civil Judicial Expertise in the European Union, online: <www.experts-institute.eu/IMG/pdf/2016_01_07_eeei_guide_to_good_pratices_egle_en_brochure.pdf> accessed 5 February 2018. 37 Organ of the Council of Europe, established on 18 September 2002 with Resolution Res (2002)12 of the Committee of Ministers of the Council of Europe. 38 Report on ‘European judicial systems –Edition 2014 (2012 data): efficiency and quality of justice’, <www.coe.int/t/dghl/cooperation/cepej/evaluation/2014/Rapport_2014_en.pdf> accessed 5 February 2018. © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: firstname.lastname@example.org This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/about_us/legal/notices)
Journal of International Dispute Settlement – Oxford University Press
Published: Apr 25, 2018
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