Revision and standardization of the Wechsler intelligence scale for children - revised (WISC-R) for the age range 13-15 years in Greece

Abstract

The WISC-R was standardized on a representative sample of Greek school children for the age range 13 - 15 in Greece. (Number of children tested in each age group was 100, total 300.). The reliabilities of the Scale are equivalent to the Americanone in the subtests and I.Q.s, ranging for T.Q.s from 0.89 to 0.93 for the Verbal Scale, from 0.83 to 0.9*1 for the Performance Scale, and from 0.92 to O.96 for the Full Scale. The validities obtained in this study between the WISC-R andteachers ratings range from O.38 to 0.62 for the 13-year-old group,from O.3O to Ο.55 for the l4-year-old group and from 0.1*1 to O.Wfor the 15-year-old group. Furthermore the intercorrelations, sex differences, age differences were found. The order of difficulty of the"items is not the same as that which is given in the WISC-R manual for each subtest, the majority of items are easier for the boys. Item validity as a whole as measuredby the biserial correlation coefficient is satisfactory for the majority of items, but the tetrachoric correlation is low. The factor analysis of this study supports the opinion of Wechsler that there is a general intelligence and his dichotomy into Verbal and Performance Scales. Our results show that general intelligence decreases as age increases. All the correlations on the socioeconomic level of the family for the 13 and 14-year-old groupswere significant at the 0.01 level. Negative correlations were found between family size and intelligence scores on all Scales for all ages. The urban children had higher I.Q.s than their rural counterparts. The better educated fathers and mothers tend to have children with higher I.Q.s. The correlation obtained for the 13 and 14-year-old groups are significant at the 0.01 level.