Qual Quant (2010) 44:59–69
In search of content validity: facet analysis
as a qualitative method to improve questionnaire
An application in health research
J. A. Landsheer · H. R. Boeije
Published online: 16 June 2008
© Springer Science+Business Media B.V. 2008
Abstract In this paper, two scales are examined for the measurement of self-regulation.
The item content is evaluated for its speciﬁc usefulness for measuring self-regulation of obes-
ity patients. Qualitative facet analysis (QFA), an application of Guttmann’s Facet Theory, is
used to investigate whether item content sufﬁciently covers the intended content area. This
form of content analysis constitutes a systematic, effective and critical tool for improving the
content validity of questionnaires. It discovers topics that are underrepresented or overrepre-
sented. The method offers a way to clarify the relationship between concrete item phrases and
the desired content as deﬁned by construct and theory. It allows the researcher to improve his
or her understanding of the items as a stimulus and of the similarities of items, and allows the
formulation of a possible structure for conﬁrmative factor analysis. Various ways to improve
the content of both scales are identiﬁed.
Keywords Content validity · Facet analysis · Qualitative method ·
Questionnaire design · Health research · Obesitas
When applied researchers develop a questionnaire for a speciﬁc and practical goal, such as
measuring self-regulation of obesity patients, the construct in question is often complex in
nature. The psychometric qualities of the questionnaire can be uncertain, and in that case
unsatisfactory results may be the result of problems with the content of the questionnaires.
The approach we wish to propose is to give the content of items a more prominent place, and
to use a systematic approach to represent the content and to facilitate the formulation of new
or additional items.
J. A. Landsheer (
) · H. R. Boeije
Department of Methodology and Statistics, Faculty of Social Sciences, Utrecht University,
P.O. Box 80140, 3508 TC Utrecht, The Netherlands