A Critique of Some Indices of Syntactic Maturity.

The need for an objective and reliable index of children's language development was recognized many years ago. In a study reported nearly forty years ago, Anderson (1937) evaluated by statistical methods three indices of language development. He analyzed data on sentence length and pronoun index but was primarily interested in the subordination index, a measure of syntactic complexity that had been devised a short time earlier by LaBrant (1933) . Anderson was concerned with the generality of LaBrant's index and in the possibility of developing an easily applied and uniform measuring device. Because of such variables as composition length, subject matter, and situations in which language is used, he drew negative conclusions about generalized application of the subordination index. He recognized, however, the existence of "... a fertile field for the development of indices based on common subject matter, well-categorized scales, and adequate samples from the standpoint of length of passage." Despite Anderson's findings, subsequent investigations of children's language relied heavily on mean sentence length and the subordination index; and, during the following twenty-five years, not much progress was made toward an easily applied and uniform index of language development. Techniques of linguistic analysis developed in the early 1960's, however, offered new hope that such an index could be devised.