This paper will outline some of the ways in which the language of the test instrument can be a factor in affecting the performance of a given child or group of children on a test. In tests of quantitative intelligence, mathematical skills, conceptual knowledge, readiness and aptitude, it is not reasonable to think of the language of the test as a neutral factor. It is with such tests that this paper is especially concerned. Particular lexical items used in a test may affect comprehension and result in false interpretations of the test performance. In analyzing the language of the test, tester and the language of the child, this paper has pointed out some ways in which children's test performance can be influenced by linguistic variables. (Author/LS)