One of the current issues in the field of programmed instruction is the effect of response mode upon learning and retention. A number of studies have indicated no difference in immediate learning as a function of various forms of overt, covert, and reading responses. However, Krumboltz and Weisman [1]* found that their written response group, when compared to those who just thought their responses and those who read the correct responses, showed significantly greater retention after a delay of two weeks. Goldbeck and Campbell [2] had eighth graders study a 32-frame program on electricity in order to test for differences in performance as a function of learning response; they used reading, writing, and thinking response groups. The results indicated significantly greater retention for the reading group after a period of ten weeks. Tobias and Weiner [3], using essentially the same design as Goldbeck and Campbell, found no differences among their groups on either immediate or delayed recall. The programs used in these studies varied in length from 32 to 177 frames.