In the field of reading, there is a great deal of interest in cohesion (Halliday and Hasan 1976), in terms of both the theoretical insights it provides and its pedagogical implications. Cohesion is a system of analysis that describes the coherence of a text as a function of semantic relations realized in surface-level features. Thus, according to Halliday and Hasan (1976:14), the textual structure in a passage such as

is created by the cohesive ties between “he” (reference) and “the gardener,” and “so” (substitution) and the proposition in the first sentence.

The proposal that the source of textual coherence is contained in surface features is an attractive one for those involved in reading, since it suggests a straightforward way to improve comprehension: teach students to attend to the cohesive devices, and their understanding of the meaning of a passage will greatly increase. There appears to be some experimental support for such a position. In the development of native language reading proficiency, Chapman (1979) found that children who were reading fluently were able to complete anaphoric relations in a cloze test, and he concluded that mastery of textual features, including cohesive ties, is a central factor in fluent reading and comprehension. A study by Cohen and his colleagues (1979, reprinted as Chapter 11 in this volume) showed that foreign readers of English in the sciences and economics did not pick up on conjunctive words in their specialized texts.