A useful summary statement of discourse factors to consider in preparing
literacy materials is by Longacre (1977). He argues that discourse is the
primary unit of linguistic structure, in the sense of being the unit which
people are aware of. Examples include functional units at the level of speech
acts and speech events: story, explanation, request, giving directions, and so
on. If literacy materials are to approximate to the actual usage of spoken
language, the choice of discourse genre is crucial. The general argument is
that materials should be in line with learners' expectancies. This general
approach fits well with Goodman and Smith's model of reading as a psycholinguistic
guessing game, although Goodman and Smith have not developed
their model at the level of discourse. An active, interpretative search for
meaning takes place at all levels of language. (For more general reviews of
the contribution of sociolinguistics to literacy teaching see Gudschinsky,
1976; Stubbs, 1980) Much discourse oriented work on the preparation of
literacy materials has been carried out by linguists working with the Summer
Institute of Linguistics. As a result, there is much work which is based on
tagmemic theory, or which is predominantly concerned with Bible translation
into exotic languages, or both (e.g. Callow, 1974).