A prescriptive theory for learning which delivers prescriptions for designing prototypes of instructional materials with different knowledge structures, the Elaboration Theory of Instruction (ETI) is based on important principles and theories of learning and instruction. This paper reports three experiments which tested ETI. The first experiment was concerned with the effect of ETI and individual differences (prior knowledge, cognitive style, anxiety, motivation, learning strategy, and attitude). Subjects were 18- to 20-year-old students in a middle technical school. The results confirmed the hypothesis that the strong structured approach of the ETI is effective for students who need external cues in the text. The second experiment, which was conducted with 14- to 15-year-old high school students, focused on the effects of synthesizers in text processing. Few differences were found between the conditions, but there was a tendency for students in the general-to-detailed sequence to perform better. The third experiment explored the possibility of using ETI for adaptive text presentation involving learner versus text control of the learning process. Subjects were undergraduate education students. It was found that students in the learner control condition retained information better and longer. The need for more research on the amount of training in the use of learner control to optimize performance is noted. A list of 32 references and 6 data tables are attached. (DJR)