Fixed sequence versus branching auto-instructional methods

"In Experiment I, three groups of 17 subjects were used to test 2 hypotheses concerning optional branching. A fixed-sequence group received items in fixed order; a back-branching group receiving the same items as the first group, was permitted to back up one item at a time to review earlier items; a third group received the same items cast in statement form and organized into paragraphs permitting subjects to choose material at their own option. A significant difference on a posttest in favor of the third group was obtained when the first and third groups were compared. In Experiment II, a computer-controlled teaching machine was used to evaluate the effectiveness of adapting sequences of teaching items on logic. Members of a branching group received sequences of items determined by the errors that were made during instruction. Each member of a fixed sequence group was paired at random with one member of the branching group . . . . Covariance analysis of criterion scores using aptitude and training time as control variables yielded no significant difference between branching and fixed-sequence conditions."