GRAND RAPIDS, Mich. - Grand Rapids and West Ottawa public schools have already announced a move back to semesters next year, while other West Michigan high schools are remaining on a trimester schedule, according to The Grand Rapids Press.

Administrators told The Press that the main reason is academic. Students need a full year to master the content in courses now required for graduation, such as algebra II, they told The Press. They also said that semester scheduling requires fewer teachers and so will save on instructional costs, according to The Press.

The semester plan typically divides the school year into two, 18-week learning periods, while trimesters divide the same time into three 12-week periods. Under the trimester system, a student would complete algebra II in 24 weeks, compared to 36 weeks under a semester plan.

"We heard from teachers over and over how challenging it is to cover all the content in a trimester," Jane DeGroot, Grand Rapids Public Schools director of secondary leadership, told The Press. Another factor is that Grand Rapids plans to switch to more online instruction next year, and that coursework is organized in semester format, according to The Press.

Meanwhile, Rockford Public Schools Superintendent Michael Shibler told The Press that trimesters give students more opportunity for elective courses like foreign language and art.

Some districts have a trimester schedule, but allow students to take more difficult courses over the course of three trimesters, The Press reported.

The Grand Rapids Press, "Two of West Michigan's largest school districts revert from trimester to semester scheduling to save money," March 26, 2010

Michigan Education Report, "New high school graduation requirements in action," May 6, 2008