Adaptation and Standardization of Snijdres- Oomen Nonverbal Intelligence test for 2.5 - 7 Years Children: A Preparatory Study

This research has been carried out with the aim of adaptation and study of psychometric properties and practicality of Snigders-Oomen nonverbal intelligence test for AWT IMAGE years children (SON-R AWT IMAGE) for Farsi-speaking children. In this study, 125 children (66 boys and 59 girls) were selected from nursery schools of the city of Tehran, which are under control of Tehran’s welfare organization. To data analysis, classical model and 2 and 3 parameter logistic model were used. Internal consistency of subtests (Mosaics, Categories, Situations and Patterns) were obtained by λ2 formula, and reliability of performance and reasoning scales and total scores estimated by stratified alpha. Reliability coefficient of subtests in total group is 0.72, 0.71, 0.67, and 0.75 respectively and reliability coefficient of performance and reasoning scales and total scores is 0.81, 0. 76, and 0.84 respectively. Various analyses were carried out about validity, including intercorrelation of subtests, item-total correlation, correlation of subtests with scales and total scores, age discrimination and discrimination power. On the whole, the results obtained from this research showed that reliability and validity of the test are high and it can be used to measure total intelligence of children. However, before standardization and norming the test in large scale, some pictures of items A, 8,9,10,12,13,14, and 15 of the categories subtest should be replaced by pictures that are familiar to Iranian children. In addition, order of items should be changed based on their difficulties.