objective Scree test ( Gorsuch & Nelson, 1981; Hakstian et al., 1982; Raı ˆche et al., 2012; Zoski & Jurs, 1996 ), parallel
analysis ( Velicer & Jackson, 1990 ), plus oblique (direct Oblimin or Promax) rotation to maximum simple structure
(Child, 2006 ). All too frequently, psychological scales have been constructed using less than optimal factor ana-
lytic methods that fail to attain maximum simple structure solutions. For example, Kaiser’s (1970) ‘Little Jiffy’
approach (principal components, with number of components determined by the eigenvalues greater than one
rule, plus orthogonal Varimax rotation) necessarily results in inflated loadings that fail to differentiate between
common factor variance, unique variance, and error variance. This crude ‘Little Jiffy’ approach has been critiqued
extensively ( Boyle et al., 1995; Cattell, 1988; McDonald, 1985 ). Maximizing the 60.10 hyperplane count ( Boyle,
2008, p. 299; Cattell, 1978, 1988 ) provides empirical evidence of the approximation to simple structure criteria.
Practicality
A scale/measure may be psychometrically sound with good reliability and validity indices and map onto a
comprehensive theoretical foundation, but if it is lengthy to complete or complex to score, then it lacks practical
utility (cf. Schuerger’s, 2008 , discussion of the Objective Analytic Battery which includes performance tests of factor
analytically derived personality trait factors, but takes more than 5 hours to administer). Also, given the high
cost of psychological assessment services, there is a trend towards having available both longer and shorter forms
of the same measure. Certainly the longer form of a measure can give more information and finer descriptions at
the subscale and item level, but short forms can well serve screening needs or an immediate estimate of the char-
acteristic being assessed. Short forms are also useful in many research studies where there is limited testing time
available due to the necessity to measure a wide range of variables. Despite the increasing popularity of short
forms in both research and professional psychology, the disadvantage is reduced reliability, in line with predic-
tions based on the Spearman /C0Brown prophecy formula (cf. Stanley, 1971 ).
Other Considerations in Scale Construction
Clearly, the psychometric attributes of reliability, standardization, validity, and utility operate conjointly. For
example, no matter how ‘elegant’ in appearance or how compelling is its ‘face validity’, a scale that incorporates
more measurement error than true score variance and is a poor predictor of relevant criteria, adds nothing or
may even detract from the very purpose for which it was intended. At the same time, adequate psychometric
characteristics, whether of a personality questionnaire, an attitude checklist, or a specific social-personality scale,
are essential for accurate measurement and assessment.
In this regard, the most frequently used response scale formats include 4-point forced-choice scales, and
5-point Likert-type scales (cf. Likert, 1932 ).Dawes (2008) investigated the effects of using 5-point, 7-point or
10-point response scale formats on mean scores, and their dispersion. He found that while use of 5-point and
7-point scales resulted in the same mean scores, use of a 10-point scale produced significantly lower (p ,.05)
mean scores (Dawes, p. 61). Accordingly, the choice of response scale format needs to be considered carefully in
constructing self-report and rating scales such as those reviewed in this book (see Carifio & Perla, 2007 ).
Hubley and Zumbo (2013) described two broad classes of psychometric theory that provide a roadmap for
developing scales/measures used in social-personality assessment, including both rational theory based
approaches as well as observed score and latent variable approaches (see also Zumbo & Rupp, 2004 ). As can be
seen in the descriptions of the various measures included in each of the following chapters, both approaches are
used in a reciprocal and complementary way in scale development, standardization and validation, irrespective
of whether or not a particular measure is based on a rational theory approach (e.g., MSCEIT; Mayer et al., 2003 )
or an empirical factor analytic approach (e.g., 16PF; Cattell & Mead, 2008 ).
The psychometric underpinnings of test construction and validation leading to the production of theoretically
and practically useful scales, much like the theories that guide them, have undergone considerable change since
the ‘brass instrument’ era of Galton or the publication of the 1939 Wechsler-Bellevue Intelligence Scale (now WAIS-
IV; see Weiss, Saklofske, Coalson, & Raiford 2010 ). Many of the scales presented in this volume were created in the
past 10 /C015 years and have been developed with an increased psychometric sophistication reflecting changes in
validity models and methods. A valid scale/measure should correlate positively with scores on other measures of
the same or similar constructs, and correlate negligibly with unrelated measures or negatively with measures of
related but different constructs (e.g., measures of curiosity correlate negatively with measures of anxiety, but they
are discrete constructs), and exhibit significant (positive or negative) correlations or standardized beta coefficients9 CRITERIA FOR SCALE EVALUATION
I. INTRODUCTION: CORE ISSUES IN ASSESSMENT