Validity, reliability, and preliminary reference values of the Stroop test (Çapa Form) in adolescents with mild...

This study examined the validity and reliability of the Stroop Test Çapa Form in adolescents with mild intellectual disability (MID) and established preliminary reference values. The sample included 29 adolescents with MID and 30 typically developing peers. Known-groups validity was assessed using Welch's Independent Samples t-tests and Cohen's d, while reliability was evaluated using Cronbach's alpha, a two-week test-retest design, Pearson's correlation, and intraclass correlation coefficients (ICC). Internal consistency was acceptable (α = 0.856). Adolescents with MID performed significantly more slowly than controls across all Stroop subtests (p < 0.001), with moderate-to-large effect sizes (d = 0.74-1.90), and showed higher error rates (p < 0.001, d = 1.47). Although spontaneous correction counts did not differ between groups, proportional correction rates indicated a moderate-to-large effect that did not remain significant after Bonferroni correction. Test-retest analyses indicated acceptable short-term stability across most Stroop dimensions, although the Stroop C subtest demonstrated comparatively weaker reliability (ICC = 0.442). Overall, the Stroop Test Çapa Form demonstrated acceptable known-groups validity and short-term reliability for assessing executive functions in adolescents with MID. The preliminary reference values provide an initial basis for interpreting Stroop performance, pending larger multicenter normative studies.