Because of a lack of systematic structuring, much of the research pertaining to the variables influencing the reader's use of context as an aid to determining the meaning of textual units is limited in its applicability. Some of the major variables that have been found to influence the reader's use of context are constraints of textual segment, word frequency, syntactic variables, and grammatical class form of a word. Theoretical models of grammar developed by linguists have provided a frame of reference within which hypotheses and the results of empirical tests can be linked together to formulate theoretical constructs directed toward new areas of reading research. Ultimately theory must include both syntactic and semantic accounts of the textual constraints used by the reader to determine meaning during the reading act. Finally, the outcome of research efforts must be translated into the reading skills language and made relevant to instructional practices. A bibliography is included. (Author/DH)