Validity of the nonreading aptitude test battery for educable mentally retarded and borderline intelligence students

Statement of Problem Individual assessment of vocational aptitude assumes a significant role in vocational guidance, vocational rehabilitation and as a criteria for placement into job training programs. A popular instrument for assessing vocational aptitude is the General Aptitude Test Battery released by the United States Training and Employment Service. Due to the nature of its composition, however, the GATE has not been considered appropriate for diagnosing vocational aptitude of mentally, culturally, or educationally disadvantaged individuals. To alleviate certain shortcomings of the GATE, the United States Training and Employment Service developed and released a nonreading edition of the GATB, appropriately called the Nonreading Aptitude Test Battery (NATB). The NATB, like the GATB, yeilds aptitude subscores that relate to 62 Occupational Aptitude Patterns contained in the test interpretation manual. An Occupational Aptitude Pattern consists of the most significant aptitudes and critical scores on these aptitudes established as minimum scores for a group of occupations having similar aptitude requirements. This research was an attempt to determine 1) the relationship between GATB and NATB OAP's for a sample of 140 mentally retarded and borderline intelligence vocational education students, 2) the relationship between Peabody Reading Comprehension Scores and GATB/NATB scores for this sample, and 3) the relationship between certain I.Q. scores and GATB/NATB scores. Method With assistance from thirteen of Vermont's Area Vocational Center guidance personnel, the GATB and NATB were administered to a sample of 180 educable mentally retarded students in special education classes. Forty students were later eliminated from the sample due to insufficient data. The data was analyzed and a series of Pearson Product-Moment Correlation coefficients were generated which showed the relationship between selected variables and the GATB and NATB tests. Results A Pearson Product-Moment Correlation coefficient of .846 was computed showing the relationship between the number of OAP's identified by both tests. The mean number of OAP's identified by the NATB (7.10) was significantly greater than the mean number of OAP's identified by the GATB (3.70). Pupils in the higher I.Q. ranges showed more OAP's than those with I.Q.'s in the lower ranges. The number of students in the lower I.Q. ranges meeting the criteria for many of the OAP's greatly increased when tested by the NATB. Also, a substantial increase in the percent of students obtaining OAP's in which a G (intelligence) or N (numerical) score was noted. For OAP's in which a V (verbal) score was present, there was not a significant increase in the number of students obtaining OAP's when tested by the NATB. It should be noted, however, that the V (verbal) segment of the NATB is being revised because the mean V (verbal) subscores rendered by the NATB have been as low or lower for the participants in this and other studies than those obtained when the same students were tested by the GATB. All of the GATB and NATB aptitude scores excepting NATB-Q and GATB-Q (clerical perception) were significantly related to full scale I.Q. scores of the sample. No difference in the relationship between Verbal I.Q. and cognitive aptitude scores of the GATB or the NATB was evident. A positive relationship existed between Performance I.Q. and all aptitude measures of the GATB and NATB with an exception for Clerical Perception-Q and Motor Coordina- tion-K on both tests. A significant relationship existed between measured reading scores and aptitude scores for G (intelligence), V (verbal ability), N (numerical ability), and K (motor coordination) on both tests. Reading ability was clearly related to performance on aptitudes G, V, and N on both tests. Conclusions The results of this study indicate that the NATB can provide valuable counseling information and should be seriously considered by counselors who are selecting vocational aptitude testing instruments for mentally retarded and borderline intelligence students.