Discusses the changes in science instruction resulting from one school's move to block scheduling. Longer class periods were found to increase the amount of concepts taught and time for activities. Figures contain a sample student schedule, goals for restructuring, rationale for block scheduling, and a sample density experiment. (LZ)

This article describes some typical 90-minute lessons in biology and chemistry designed for use with block scheduling. The lessons illustrate the benefits of block scheduling to science instruction. Contains an example of one day's block scheduling of science and mathematics courses. (LZ)