material. A rough sketch of discourse classes from more specific to more general (i.e. in the direction of greater generalization) is given in Table 1. Table 1: Discourse categories CL and assumption 2(c) In this case a language class is taught with the intention of aiding the L2 students' achievement in content classes, i.e., LT -CL. This discussion should go beyond the case where a general basic ESL course teaches a student some English with the result that the student can make some sense of any content course he takes later. This is likely to happen to some degree with any language course and requires no particular curriculum planning. It is desirable, too, that it go beyond the case where the language course has the limited objective of helping the student through the content in a particular lesson or unit, since this is similar to the objective of L, teaching combined with content teaching. The aim should be more general and long-term: to see what LT curriculum can help students manage content learning tasks independently. This is particularly important in the higher grades in the school system where the content is more abstract, the language demands are more intense (more lecturing, more reading and writing), and the student has a decreasing number of years to catch up in language and content achievement. Two ESL models for L. teaching for content learning are English for special purposes and ESL study skills courses, (e.g., Yorkey 1970). Both assume that LT -> CL, and would be redundant if they did not, but there do not appear to be any studies which test this assumption. A third model, developed for L1 students, is reading and study skills in the content areas, and here there is some evidence for LT CL. Thus Schiller (1963) found that the systematic use of study skills in social studies promoted a significant increase in geography achievement. 179 This content downloaded from 157.55.39.207 on Thu, 20 Oct 2016 04:13:58 UTC All use subject to http://about.jstor.org/terms