Focusing on variables linking fourth graders' reading comprehension and writing ability, a study investigated the (1) relationship between both free recall and comprehension probe scores in reading and analytical scale scores in writing, (2) effects of reading and writing competence on the production of story grammar categories in writing, (3) relationship between writing scores and the components of the analytic writing scale, and (4) qualitative differences in students' use of story grammar categories in both their reading recall protocols and independent writing samples. Subjects, 36 fourth graders from two Canadian schools grouped according to high, average, or low reading ability, read and responded to two passages (one with two ideally structured passages, the other with two ideally structured stories), and produced writing samples in the classroom over a 4-week period. Analyses of responses and writing samples indicated that reading comprehension and writing ability measures were significantly related; that the ability to recall story grammar elements during reading was not indicative of the ability to produce the same elements in writing; that the mechanics and story grammar category components of the analytic writing scale were the best predictors of writing quality; and that good readers and good writers, as assessed by the number of propositions recalled in reading and produced in writing samples, are not necessarily one and the same. (Twelve references are included.) (JD)