Test-retest reliability of the test for auditory comprehension of language when it is used with mentally retarded children.

The Carrow (1973) Test for Auditory Comprehension of Language (TACL) is used frequently as part of a test battery to assess the language skills of mentally retarded children. This study determined its reliability with this population using a test-retest paradigm. Forty-four retarded children were given the test and then retested after a five-week interval. A reliability coefficient of 0.91 was obtained between pre-test and posttest administrations of the TACL. Internal stability was highest for total scores, the subtests measuring form class and function words, and grammatical categories. The low coefficients obtained for the subtests of morphological construction and syntactic suggest that these should be viewed with considerable caution when considered separately from the total test results.