Conducted as the third in a series of four investigations of teacher explanation of reading skills, a study examined the relationship between explicit teacher explanation and student awareness of lesson content and reading achievement gains. Subjects were seven fifth-grade teachers and their respective low-reading ability groups. The teachers were taught how to modify basal text prescriptions for a particular skill so that students would learn to use it as a strategy for discovering meaning rather than as a memorization exercise. In addition, the teachers were taught how to organize and structure a lesson so that students were explicitly introduced to a skill, had a model to follow, and were guided in applying it in a "real text." Data were collected by means of audiotapes of lessons and teachers' perceptions of the training they had received, student interviews, and pretests and posttests of student achievement. Results support earlier findings that teachers can be trained to be more explicit in their explanations and that such explicitness is related to improved student awareness of lesson content. As in earlier studies, however, no significant improvement was found in student achievement. Materials used in the training program and study are provided in seven appendixes making up the greater part of the document. Materials include rating forms, interview protocols, criterion measures, and a graded oral reading paragraph test. (FL)