Background: Cluster-randomized experiments that assign intact groups such as schools or school districts to treatment conditions are increasingly common in educational research. Such experiments are inherently multilevel designs whose sensitivity (statistical power and precision of estimates) depends on the variance decomposition across levels.…

Although the four-day school week originated in 1936, it was not widely implemented until 1973 when there was a need to conserve energy and reduce operating costs. This study investigated how achievement tests scores of schools with a four-day school week compared with schools with a traditional five-day school week. The study focused on student…

This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Colorado students showed gains in reading at the proficient level for racial/ethnic subgroups, low income students, and boys and girls. There were slight declines or flat trends for almost all subgroups at the advanced level in reading. In math, gains were…

This year the Center on Education Policy (CEP) analyzed data on the achievement of different groups of students in two distinct ways. First, it looked at grade 4 test results to determine whether the performance of various groups improved at three achievement levels--basic and above, proficient and above, and advanced. Second, it looked at gaps…