A study in the relationship of mental ability with age, sex, and school achievement of secondary school students in the republic of Yemen

Abstract

The aim of this study is to examine the relationship of intelligence scores with Age, Sex and school achievement of Secondary School Students in the Republic of Yemen. For this purpose the Otis-Lennon Mental Ability Test Advanced Level Form K (OLMAT) (1967) was adapted to suit the Yemeni environment. The sample of this study consisted of 1561 students. Of this, 801 were males and 760 were females; 682 were from the tenth grade, 466 were from eleventh, and 413 were from the twelfth grade. A total of 47 classes for both sexes were randomly selected: 24 classes for boys, ten classes for tenth grade, seven classes for eleventh grade, and seven classes for twelfth grade. Out of 23 classes for girls, nine classes were for tenth grade, seven classes were for eleventh grade, and seven classes were for twelfth grade. The researcher used the Otis- Lennon Mental Ability Test (OLMAT) advanced level form (K). The original OLMAT (80 items) was translated to Arabic language. Some items were changed and modified to suit the Yemeni culture. The Arabic adaptation of OLMAT was administered to the study sample. Difficulty values and discrimination values were estimated for each item. The reliability coefficients were obtained by test-retest method and split-half method for the entire sample and for different grade levels. Construct, concurrent and discriminant validity were established and were found to be significantly high. The reliability and validity results revealed that the Arabic version of OLMAT advanced level form K was highly reliable and valid. Age norms and grade norms were derived for the entire sample and for different age and different grade levels by various types of scores: Percentile Ranks, z-scores, T-scores, Deviation IQ (DIQ) and Stanines. The differences between students scores in intelligence in different age groups were tested using ANOVA, and the differences in intelligence scores between males and females and between high and low school achievement were tested using t- test. The relationship (Point-biserial correlation, Pearson correlation coefficient) between intelligence students’ scores and their age, sex and school achievement was tested. The multiple regression analysis helps to predict school achievement by using different subtests of intelligence (mental ability). The results of the differences between intelligence (mental ability) scores of students according to their age show that there were significant differences between all of mean scores for all age levels except between 15 and 16 year old students in subtests of verbal comprehension and figural reasoning and 18 and 19 years old students for the total test and for each subtest.