Describes development of a causal model to test effects of scholastic ability, computing attitudes, and computing background of university undergraduates on use of a computer-assisted instructional system, PLATO-LDEC; on attitudes toward PLATO-LDEC; on computing attitudes after students' PLATO-LDEC experience; and on course grade. (Author/MBR)

Describes a study of high school students that investigated the use of microcomputers to teach principles relating to the design and interpretation of graphs. Results related to student achievement, higher order thinking skills, and behavioral protocols are discussed. A sample assignment sheet and test questions are appended. (66 references) (LRW)