Abstract:
In a national survey, Piotrowski and Keller (1989) found the Wechsler Adult Intelligence Scale -Revised (WAIS-R) was the second most popular psychological and/or educational test administered to adults. Information derived from the scales has many uses, including placement in schools, clinical diagnosis, and assessing neuropsychological damage. Therefore, the WAIS-R's reliability in all age groups is crucial.
One method of assessing a test's stability is administering the same test twice with a specified time interval and then correlating the scores from the two testings. Wechsler (1981) published normative data in the WAIS-R manual for the retest reliability of only the 25 to 34 age group and the 45 to 54 age group, leaving seven age groups unexamined, including the 18 and 19 age group. Wechsler suggested further research be done on groups of differing ability levels. Previous research has suggested the WAIS-R's stability is suspect in the under 20 age groups. The present study was designed to investigate the retest stability and the magnitude of practice effects evidenced when the WAIS-R was utilized in the 18 and 19 age group. Wechsler (1981) exerted considerable effort to insure no gender bias existed in the WAIS-R; however, gender differences have been noted in several studies, therefore, the effect of gender on gains in IQ scores was examined in this study.
In the current study, 44 18 and 19 year-old college students (15 males, 29 females) who were enrolled in undergraduate classes, were tested twice within a two-month period, similar to the process employed by Wechsler. Retest correlations ranged from .62 to .89 for the combined sample on the eleven subtests and were. 90, .88, and .94 for the Verbal Performance, and Full Scale IQs, respectively. Furthermore, the men gained significantly more on Verbal and Full Scale IQs from test to retest.
