Since about 1962, researchers have explored the effectiveness of educational software in the schools under various conditions, and many have concluded that computer assisted instruction (CAI) is effective. Many of the studies reviewed to support this conclusion, however, had design flaws. Reviews of educational software effectiveness studies have…

Criticizes the statistical methods used in a previously published article that compared a commercially produced computer program with traditional teaching methods. Measures of instructional effectiveness are described, the assignment of student pairs is examined, and the use of blocking variables with analysis of variance is discussed. (LRW)