Psychometric Evaluation of the Receptive Picture Vocabulary Test for Persian-speaking Children

Background and Objectives: Measuring children’s receptive vocabulary skills requires the use of valid and reliable tools. This study aims to assess the reliability of the receptive picture vocabulary test for Persian-speaking children (RPVT-P). Methods: In the first phase of this cross-sectional, descriptive, and analytical study, 434 normal children aged 30 to 71 months participated. In the second phase of the study, 2 groups participated, 16 children with Down syndrome (DS) a mentally age-matched typically developing (TD) peers. The internal consistency (Cronbach’s α coefficient), construct validity, and discriminant validity of the RPVT-P was evaluated. Results: Cronbach’s α was calculated as 0.825, indicating good internal consistency for the total score of the RPVT-P. The Spearman correlation coefficient of 0.83 showed a positive correlation between age and the total score of the RPVT-P (P=0.0000). The correlation between most of the subtest scores and the total score of the RPVT-P was found from 0.70 to 0.87, showing acceptable construct validity. A significant difference was observed between the DS and TD groups for the total scores of the RPVT-P (P=0.0000), indicating good discriminant validity of the RPVT-P. Conclusion: The RPVT-P is a test with acceptable validity and reliability to determine the ability of preschool Persian-speaking children in receptive vocabulary