Date of Award


Document Type


Degree Name

Master of Science (MS)




The purpose of this research was to compare the Illinois Test of Psycholinguistic Abilities and the Parsons Language Sample in assessing the linguistic functioning of institutionalized mentally retarded children. A stratified sample of mentally retarded children was administered both the ITPA and PLS in counterbalanced order. The results were correlated through the Pearson product-moment correlation coefficient and the correlation matrix analyzed through a principle-components factor analysis. The ITPA, PLS comparison produced high correlation coefficients with the exception of the Intraverbal Gesture sub-test of the PLS. The factor analysis of the correlation matrix revealed one or more sub-tests had high loadings on five different factors. Sub-tests of both the ITPA and PLS had high loadings on "Immediate Recall of Auditory Symbols," "General Linguistic Ability," and "Comprehension and Expression." The other two factors, "Imitation of a Motor Act," and "The Ability to Make a Gestural Response to a Verbal stimulus," each had one sub-test of the PLS highly loaded on it. The results of the factor analysis suggested with mentally retarded children Vocal and Motor Encoding tests may be more a test of comprehension than encoding ability and that "Imitation of a Motor Act," is an aspect of linguistic functioning sampled by the PLS but not the ITPA.


vi, 160 leaves : ill. ; 28 cm. Bibliography: leaves 155-160.

Included in

Psychology Commons


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