Present school programs place considerable reliance on the results of standardized language tests both as placement and diagnostic devices, yet the validity of these tests is open to question. Certain questions arise in light of current theory and research. To what extent are currently available measuring techniques useful for identifying the characteristics of linguistically different learners? Are they helpful in planning instructional strategies? How might the learning potentialities of linguistically different learners be measured? What are the high-priority test needs? Two main branches of investigation exist: the individual's ability in language as contrasted with his ability in standard language. Current understanding of language, language learning, and curriculum design indicates some confusion of goals in these three areas which must be clarified before test findings may be used with the same meaning in each area. (Author/VM)