Warren County (North Carolina) High School is in its fourth year of a plan that divides the 180-day school year into three 60-day trimesters. Each day contains four class periods, and each trimester-long course earns students one-half credit. All students and teachers are rescheduled at the beginning of each trimester. The plan's many advantages…

One result of the extraordinarily rapid pace of educational reform in recent decades has been public expectation of greater accountability for the more than $300 billion spent annually on schools. As reformers have sought better ways to utilize all resources, including instructional time, block scheduling has been developed as a more efficient way…