"The objectives of this research were: To devise and test instructional materials for teacher intervention in students 'expository writing processes with the aim of shaping student thinking and writing behaviour in the direction of the norms of school-based expository text-types ; To evaluate the effect, on student writing, of explicit instruction in cognitive procedures and genre practices associated with school-based expository text-types ; To determine the viability of moving from a grammar- and topic knowledge-focused approach to teaching expository writing to an approach that prioritises the teaching of the thinking processes and social practices of expository writing." -- p. 2.