This fall, Forest Lake High School will make its biggest schedule change in a dozen years, altering its four-period block system in a move largely driven by concerns the schedule might hamper students' performance on No Child Left Behind assessments.

The high school joins a move away from the block schedule, which runs on 85-minute classes and condenses yearlong courses into a semester, in favor of one that teaches core subjects 50 minutes a day for the entire school year.

The North St. Paul-Maplewood-Oakdale and Stillwater districts also abandoned a block schedule in the past three years.

The new system eliminates the learning gaps that might have students taking the MCA-II test -- the state's No Child Left Behind assessment -- a full year after their last math class.

"If we take kids out for half a year and expect them to do well on state exams, we're fooling ourselves," Principal Steve Massey said.

While the school reached No Child Left Behind goals in all areas except reading for special education students last year, Massey said he was also concerned with long breaks before college entrance exams and Advanced Placement tests.

Its solution, approved 7-0 by the school board on Thursday night, is actually a hybrid of the block schedule and a traditional slate with seven 50-minute periods.

Students will take three 50-minute semester-long classes and a pair of 90-minute blocks that switch every quarter, meaning students will take core classes such as math and English for two semesters instead of one.

Massey cited a 2006 study from the Washington School Research Center showing students on seven-period and modified block schedules performed best on that state's No Child Left Behind tests. Students on a four-period schedule were among the worst.

And when test scores mean everything to schools, it's no surprise the four-period day is falling out of favor, Minnesota Association of School Administrators executive director Charlie Kyte said.

"We're doing more testing now than we used to do," Kyte said. "For the courses that are more vocationally oriented, [the blocks] are super. Now the cycle has swung back, we're concentrating on academic education and it lends itself to that shorter period approach."

Kyte also suggested the testing-intensive environment emphasizes underperforming students instead of advanced learners. Forest Lake's proposal prompted a petition signed by more than 75 students angry that the new schedule will cost them two electives over the course of the school year.

School board President Bill Bresin hopes, over time, those students will see the benefits in the courses they do take.

"These are high-potential students who want to take all the courses," he said. "They're worried about losing classes. But we'll hopefully see the stats on the test scores improve."

The reaction from teachers, Massey said, was mixed. But he knows they understand the reasons behind the switch.

"There's a growing appreciation for the reality we face [with tests]," he said. "Whether we like it or not, there's a recognition those are the real issues."

Ben Goessling • 651-298-1546