An approach to improving classroom instruction is offered that advances a longitudinal, cyclical presentation of instruction, its evaluation, and revision over time. This approach is distinguished by student self-graphing of student performances, a teacher's log of changes made in instruction, and a class graph kept by the teacher or students. The teacher's involvement with this approach can be gradual, beginning with graphs for longitudinal lesson plans with pre-post assessments and going as far as multiple longitudinal assessments with teachers acting as researchers. (Contains 2 figures.)