The conceptual base of a project that examined teachers' explanations of reading skills and strategies to low-ability students is reviewed in this paper. Following a brief discussion of the background of the project, the paper explores the curricular conceptions underlying it. Specifically discussed are two views of how direct instruction should be used to improve comprehension, the first arguing that comprehension is developed primarily through direct instruction in the content of the text, the second holding that it is developed through direct instruction in the process by which content is understood--the view that undergirds the Teacher Explanation Project. The paper next examines the instructional conception guiding the project, which is based on four characteristics of effective teacher explanation: (1) a responsiveness to student restructuring of information; (2) an effort to put students in conscious control by creating awareness; (3) the presentation of declarative, conditional, and procedural information that is conceptually accurate, explicit, meaningful, and sequenced; and (4) assistance for students as they build understandings by providing sequencing and restructuring "hooks." A list of 64 references is appended. (FL)