Construct Validity, Test-Retest Reliability, and Internal Consistency of the Photo Elicitation Semantic Differential Scale (PESD) in Disability Studies

The Photo Elicitation Semantic Differential scale (PESD), developed to examine the social perception of disability and attitudes towards people with a disability (PwD), comprises six dimensions: communicativeness, competence, attractiveness, intelligence, industriousness, and popularity. This paper aims to assess the construct validity, test-retest reliability, and internal consistency of the PESD. A longitudinal study with 40 participants of the Swiss general population and 2 (test-retest) * 8 (different photographs) measurements per subject was performed. Construct validity was examined via Principal Component Analysis (PCA), test-retest reliability via the Intraclass Correlation Coefficient (ICC) and a frequency analysis of deviations among test-retest scores, and internal consistency via Cronbach's alpha. PCA extracted two factors corresponding to hard and soft skills for the test and a single factor for the retest. ICCs ranged from 0.44 (industriousness) to 0.60 (intelligence). Deviations between tests exceeding +/-1 were rather rare ranging from 6% (intelligence) to 14% (competence). Cronbach's alpha equalled 0.814 and 0.858 for test and retest, respectively. Summarising, in our study the PESD appears to be a valid and reliable tool for the examination of the social perception of disability and attitudes towards PwD.