Adaptation of the Wechsler Adult Intelligence Scale in Bangladesh Context

Abstract

The objective of the present study was to adapt Wechsler Adult Intelligence Scale-WAIS-III for use in Bangladesh. The WAIS-III is a standard assessment tool developed by Wechsler (1997), which measures intelligence and cognitive ability in adults and older adolescences. It consists of fourteen subtest seven verbal and seven performance tests. The researchers followed standard adaptation procedures to adapt the scale into Bangla. The study comprised of four phases; translation of the scale, item analysis, measurement of reliability and determining validity. In the first phase, the scale was translated into Bangla and reviewed by five Judges. Based on their suggestions as well as the judgment of the supervisor of the research, some modifications were made and the final version of the questionnaire was prepared. For item analysis, the translated version was administered to total of 15 respondents (seven male eight female) aged between 20 and 21 years, using incidental sampling techniques. Based on the responses of the participants, assessments of the Judges and the suggestions from the supervisor further modifications were made of the verbal items and the final form of the scale was prepared. In the process of determining reliability, split-half reliability coefficients were calculated for each sub-test. The coefficients were as follows: .957 for vocabulary, .776 for similarity, .831 for arithmetic, .862 for digit span, .898 for information, .759 for comprehension, .894 for letter number sequence, .862 for picture completion, .886 for block design, .897 for matrix reasoning, .871 for picture arrangement and .686 for object assembly. Coefficient alpha was also calculated and found to be, .906 for vocabulary, .774 for similarity, .805 for arithmetic, .787 for digit span, .825 for information, .755 for comprehension, .737 for letter number sequence, .612 for picture completion, .886 for matrix reasoning, .619 for picture arrangement and .657 for object assembly. All of these reliability coefficients were found to be significant. The scale was given twice, one week apart, to a sample of 20 responders in order to evaluate test retest reliability. Using Pearson's product-moment correlation, the results from the two tests were associated. The reliability coefficients for digit symbol coding, digit symbol copy, and symbol search were determined to be.980, .916 and.964 respectively. The test retest correlation coefficients were all.01 level significant. Through face validity and content ix validity, the scale's validity was guaranteed. The Bangla version of the WAIS-III has been shown to have a satisfactory level of validity. In conclusion, the Bangla version of WAIS-III was found to be reliable and valid within the context of Bangladesh. This scale can be utilized in clinical setting and various other sectors to assess an individual’s intelligence.