Date of Award

Summer 7-1970

Document Type


Degree Name

Master of Science (MS)




This study was a preliminary endeavor concerned with an investigation into whether young adults of defined age ranges and defined intellectual levels obtain significantly different scores on the Digit Symbol sub-test of the WAIS.

With the confidence level set at .05, the null hypothesis that there was no significant difference between the Digit Symbol sub-test scores of the retarded, normal, and superior groups was tested. The term young adults was used to describe subjects between the ages of seventeen and twenty-five. The intellectual level defined as retarded, included Intelligence Quotient scores between 50 and 70; the normal level had Intelligence Quotient scores between 90 and 110; the superior level had Intelligence Quotient scores at 120 and above.

Subjects for the retarded group were obtained from the Joplin Area Sheltered Workshop, and from Nevada State Hospital Number Three, Nevada, Missouri. Due to the requirements imposed upon the retarded group, only thirty subjects were found who met the requirements. All thirty agreed to take part in the study. All were administered the Digit Symbol sub-test of the WAIS in accordance with the manual instructions.

Subjects for the normal and superior groups were obtained at Missouri Southern College, Joplin, Missouri. Since recent Intelligence Quotients were not available for the students, one hundred and fifty Otis Quick-Scoring Mental Ability Tests, Gamma test: Form AM, were administered to classes the psychology staff felt would have either a majority of students with an Intelligence Quotient range between 90 and 110, or 120 and above.

As the Otis tests were graded, the scores were listed as normal, superior, or not usable. The normal group had thirty-six qualifying scores; the superior group had thirty-four qualifying scores. The subjects of both groups were interviewed just prior to testing to determine if they met all the requirements imposed upon their respective groups. Only three subjects from the normal group were excluded. In both groups, only the first thirty Qualifying subjects were administered the Digit symbol sub-test of the WAIS.

The Kruskal-Wallis one-way analysis of variance was used to test the null hypothesis. A significant difference between the three groups was found to be above the .001 level of confidence. Thus, the null hypothesis was rejected. It was concluded that people with higher Intelligence quotients score significantly higher on the Digit Symbol sub-test of the WAIS than people with lower Intelligence Quotients.


vi, 37 leaves : ill. ; 28 cm. Bibliography: leaves 36-37.

Appendixes: Otis quick-scoring mental ability tests Gamma / Arthur S. Otis (c1937) and WAIS record form (c1955).



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.