Construction, Validation & Investigating Reliability of the Language Development Scale of Children

The purpose of recent study was construction, investigating validity and reliability of the Language Development Scale of Children. Research method was descriptive, test making type. In first step, the Language Development Scale of Children was designed based on the theoretical and experimental foundations and developmental competences of children. 52 children (girls & boys) were selected by multi-stage cluster sampling method from Isfahan's nurseries, preschool centers and primary schools of 6 educational districts, then it was performed on them and the psychometric properties were measured. In second step 200 children were selected in the way of Cochran from these centers. To study reliability and validity of instrument the sample group completed the Language Development Scale of Children and Vineland Adaptive Behavior Scale. To investigating the reliability, Cronbach Alpha and for validity of instrument validity exploratory factor analysis method and criterion validity were used. Results showed the total internal consistency of the Language Development Scale of Children was 0. 98 and subscales internal consistency was 0. 96. The results of exploratory factor analysis method showed two factors model of the Language Development Scale of Children including, Receptive language subscale and Expressive language subscale. These two factors explained 54. 91 variance of the total scale. Also the correlation coefficient between the Language Development Scale of Children and Vineland Adaptive Behavior Scale was 0. 91, which indicated satisfactory criterion validity for the Language Development Scale of Children. Confirmatory the Language Development Scale of Isfahan's Children has appropriate reliability and validity for evaluating development of receptive and expressive language in children under 8 years old.