Three-Factor Scale of Social Identity: Evidence of its Psychometric Adequacy

Abstract The objective of this study was to verify empirical evidence of the psychometric (validity and reliability) adequacy of the ThreeFactor Scale of Social Identity (ETIS), based on two studies. The sample in study 1 was composed by 465 military policemen from the Brazilian Federal District, 88% male, with mean age of 38.78 years (SD=7.08). They filled the questionnaire with the ETIS and demographic questions. Using a Principal Components Analysis, a three-factor structure was observed, with Cronbach’s alphas of 0.83 (centrality), 0.82 (affect) and 0.86 (ties). The sample in study 2 was composed by 451 military policemen from the Brazilian Federal District, 88.7% male with a mean age of 39.25 years (SD=6.73). The three-factor structure was tested through Confirmatory Factor Analysis. The adjustment indexes were satisfactory (Χ2/g.l.=2.67; CFI=0.98; GFI=0.98; RMSEA=0.061). Reliability, measured by Jöreskog’s Rho, was adequate, being 0.87 (centrality), 0.87 (affect), and 0.91 (ties). The indicators of the exploratory and confirmatory study demonstrated satisfactory psychometric adequacy. Finally, ETIS showed convergent and discriminant validity for the professional context.