The psychometric properties of the Forensic Stigma Scale (FSS)

Three studies examined the psychometric properties of a new scale, the Forensic Stigma Scale (FSS), designed to measure public stigma of forensic patients. In Study 1, the initial item pool was derived to measure three components of stigma (stereotypes, prejudice, discrimination). An EFA (n = 218) identified a two-factor model with 12 items. In Study 2, this two-factor solution was confirmed using CFA with a separate sample (n = 326) which had good-excellent fit indices. All 12 items loaded (> 0.40) on the two latent factors (Dangerousness/Unpredictability [7 items] and Responsibility/Blame [5 items]) identified in the EFA. In Study 3, using the combined samples from the previous two studies, the 12-item FSS showed promising internal consistency reliability (0.75-0.80) and demonstrated satisfactory-good criterion validity; the scale was moderately correlated with a similar construct and was able to differentiate individuals who did and did not have specific education on forensic psychology. IRT analyses demonstrated that both subscales had discrimination parameters in the moderate-high range (α = 1.03 to 2.54), though the threshold parameters (b_i) on the Dangerousness/Unpredictability subscale showed better distribution across trait levels. Overall, the 12-item FSS demonstrates strong psychometric properties, especially the Dangerousness/Unpredictability subscale. The scale may provide clinical and empirical uses for measuring public stigma of forensic patients.