Quality & Quantity 33: 1–12, 1999.
© 1999 Kluwer Academic Publishers. Printed in the Netherlands.
Trust and Understanding, Two Psychological
Aspects of Randomized Response
A Study of a Method for Improving the Estimate of Social Security Fraud
JOHANNES A. LANDSHEER
, PETER VAN DER HEIJDEN
and GER VAN
Department of Methodology and Statistics, Utrecht University, Heidelberglaan 2, PO Box 80140,
3582 TC Utrecht, The Netherlands;
Boa, Nieuwe Gracht 98, 3512 LX Utrecht, The Netherlands.
Author for correspondence: Johannes A. (“Hans”) Landsheer, E-mail: J.A.Landsheer@fss.uu.nl
Abstract. This study examines two different Randomized Response methods to see whether they
evoke sufﬁcient understanding and trust, and ensure fewer evasive answers to socially sensitive
questions. Two Randomized Response methods were employed by trained interviewers to study
fraud: the Forced Response method, using dice, and Kuk’s method, using playing cards. Respon-
dents were selected from the ﬁles of the social security ofﬁces of three Dutch cities. A total of
334 respondents participated voluntarily in this study of two Randomized Response methods. Most
respondents were known to have committed some form of fraud, and their answer on the Randomized
Response question is validated with this information. The results indicate that subjects who have a
better understanding of the Forced Response technique give more socially undesirable answers. The
interviewer has a most important role establishing trust and understanding. Respondents who are
less able to understand the instructions, e.g., have limited language abilities, develop less trust in the
Key words: measures–instruments, social service clients, fraud estimates, Netherlands.
The Randomized Response technique, originally developed by Warner (1965), is
intended to minimize evasive responses to sensitive social questions. All Random-
ized Response techniques use a randomizing device, such as dice or playing cards.
Depending on the result produced by the randomizing device, the answer is based
on the true status of the respondent or is without meaning. Because both interviewer
and researcher are unaware of the result of the randomizing device, the use of
this device ensures that an individual respondent cannot be identiﬁed on the basis
of his/her answer. Aggregate estimates of the responses to the sensitive questions
remain possible while the privacy of the individual respondent is protected. Since
the ﬁrst introduction of the Randomized Response method, researchers have pro-
posed improvements (Fox & Tracy, 1986; Umesh & Peterson, 1991) for making
the technique statistically more efﬁcient.