Constructing validity: Basic issues in objective scale development.

Abstract

because a review of the recent literature indicates that they are still not universally honored.We focus on verbally mediated measures; thus, for example, we do not address the development of behavioral observation scales. Moreover, our primary focus is on self-report measures, because these constitute the majority (67%) of our reference sample. Nonetheless, most of the basic principles we articulate are applicable to interview-based measures and rating scales designed to be completed by clinicians, parents, teachers, spouses, peers, and so forth.Before proceeding further, it is interesting to examine the new measures comprising our Psychological Assessment sample. This examination sample offers a glimpse at why scale development continues unabated, as well as the nature of the unmet needs these scale developers are seeking to fill. First, not surprisingly given this journal's focus, more than half (61%) of the scales assess some aspect of psychopathology, personality, or adjustment. The next most common categories are measures of attitudes and interpersonal relations (20% and 15%, respectively). The remaining scales assess a miscellany of behaviors, abilities, response validity, trauma experience, and so forth. In all categories, most new scales apparently tap relatively narrow constructs, such as suicidality, fear of intimacy, We wish to acknowledge the helpful comments of Jane Loevinger on a previous version of this article.

Factorial invariance of posttraumatic stress disorder symptoms across three veteran samples

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Development and Evaluation of the Dutch Clinician-Administered PTSD Scale for DSM-5 (CAPS-5)

“…Internal consistency was evaluated with Cronbach’s alpha, inter-item correlations, and item-total correlations. Internal consistency can be considered good when Cronbach’s alpha for the total scale is > .80 and most inter-item correlations are in the recommended range of moderate magnitude of .15–.50 (Clark & Watson, 1995). Because Cronbach’s alpha is a function of scale length, it was expected to be lower for the symptom clusters Re-experiencing (5 items), Negative alterations in cognitions and mood (7 items), Arousal (6 items), and especially Avoidance (2 items) compared to the total scale.…”

A psychometric assessment of Disturbances in Self-Organization symptom indicators for ICD-11 Complex PTSD using the International Trauma Questionnaire

“…The performance of the items was assessed according to four a priori criteria. These criteria were originally proposed by Clarke and Watson (1995) to ensure that: (1) the maximal amount of item level information is retained, (2) attenuated correlations were avoided, and (3) the measure has the ability to discriminate at different points on the underlying continuum. These criteria have been formalized by Lamping et al (2002) who proposed explicit cut-off values; these cut-off values are helpful in evaluating item performance, but we apply them descriptively rather than prescriptively, as the appropriateness of the values may differ depending on the nature of the instrument being developed.…”