The concept of "block scheduling" teaching in 90- rather than 45-minute periods swept through US high schools in the 1990s. But today, opinions on its degree of success run the gamut from upbeat and positive to angry and condemnatory.
"It's all less hectic," says Carol Ladd, a German teacher at Marnacock High School in Readfield, Maine, where block scheduling has been in place for four years. "There's time to introduce material, then manipulate and reinforce it. Retention is better." Students and faculty alike embrace the idea at her school, she says.
But at Martin Luther King Jr. Senior High School in Philadelphia, not everyone shares that sentiment. "It's absolutely horrible," says Lynn Dixon, an English teacher at the school, where block scheduling has been in effect for four years. "The kids are wildly bored, the teachers are wildly bored, discipline is worse, and the kids are out of the loop for standardized tests."
Some faculty have actually quit in frustration over the system, says Ms. Dixon.
Now fresh research is roiling the block-scheduling debate. A study of Illinois and Iowa high schools done by Iowa State University and the administrators of the ACT assessment suggests that the system causes student scores on the ACT to decline.
It's not the first time block scheduling has been called into question. The idea of turning high school classes into longer, more intense study units like those a college student might experience has come under fire in recent years. One frustrated Wisconsin parent maintains a website that includes an exhaustive index of negative research findings on block scheduling (www.jefflindsay.com/Block.shtml).
But block scheduling still has its enthusiastic supporters. The idea was made popular in recent decades by school reformers, who questioned the almost universally accepted tradition, in place since the early 1900s, of requiring all high school classes to meet for 45 to 50 minutes every school day.
Lengthening class periods, they recommended, would force teachers out of a lecture-only mode of teaching, allow students to engage more deeply in material, and cut down on disciplinary problems and time wasted in the hall between classes. The idea gained momentum rapidly throughout the 1990s and got a significant boost in 1994, when the National Education Commission released its "Prisoners of Time" report, which included a recommendation that high schools experiment with block scheduling.
Between 25 and 40 percent of high schools now use block scheduling, according to some estimates. In some states, that figure is significantly higher. In North Carolina, for instance, almost 90 percent of high schools have embraced the system. Some middle schools across the country have also moved toward the longer class periods.
There are two basic models for block scheduling. One, known as the 4 x 4, requires students to take four lengthy classes a day for a semester. The next semester, they move on to four different subjects.
The other model is sometimes called an A-B-A-B, or alternating system. Students have four extended class periods a day, but then alternate with four different classes the next day, allowing them to take eight classes spread out over the course of the school year.
The 4 x 4 is the system that comes in for the heaviest criticism, in part because it leaves lengthy time gaps in the academic sequence. A student who takes geometry in the fall of his sophomore year, for instance, may not have a math class again until the fall or spring of his junior year. The Iowa State study indicated that schools on the 4 x 4 system showed more dramatic declines on the ACT.
"It's easier to retain information when you spread it out through the year," says Heather McKelvey, who just graduated from Martin Luther King Jr. Senior High School. She found that staying away from studies like math for months at a time made it hard to stay sharp. "It would take me at least a week just to remember where to put the exponents and how to set up the equations."
She succeeded in the end, but says she felt she was fighting against the block system rather than being helped by it.
Shariff Dunlap, a junior at King who failed both chemistry and Spanish, says he felt defeated by the system. "The periods are so long and boring, and it makes the kids be bad and talk too much during class," he says. He's also worried now about repeating Spanish this fall after a gap of almost nine months. "I don't remember any of it now," he says.
At Creston High School in Iowa, where an alternating block schedule has been in effect for seven years now, principal Todd Wolverton says test scores have remained steady, despite early hopes that the new schedule would spur academic improvement.
But in terms of atmospherics, Mr. Wolverton says block scheduling has been good for his school.
Students now take more classes, experience fewer disciplinary problems, and have better attendance. "It's been great for our chemistry classes and some of our vocational classes. In home ec you can bake the cookies and eat them, too," he says.
Math teachers in his school still dislike it, says Steve Westerberg, principal of Denison High School in Iowa. But he estimates that 90 to 95 percent of the faculty favor the block system they've now used for seven years.
"It gets teachers away from just lecturing and provides good opportunities for staff development," he says. It also allows short local field trips like visits to a courthouse or conservation site to take place during class time.
But he also cautions against expecting too much from the system. "It's just an arrangement of time. If schools are looking for a magic bullet, this isn't it."
Students have time to learn a subject matter in greater depth.
Schools with block schedules tend to give fewer failing grades and have lower dropout rates and fewer discipline problems.
Less time is lost in the halls between classes.
There is more time for student-teacher interaction, group work, discussion, labs, field trips, and other projects, including off-site employment or internships.
There is more time for teacher planning.
Longer time gaps between instruction and standardized exams may hurt test scores.
Student absences of even a day or two are hard to make up.
Transfers from school to school become more difficult.
Many teachers have not been trained to engage students in periods as long as 90 minutes.
Some subjects requiring regular repetition and dependent on a particular sequence of lessons like math, foreign language, and music can be particularly difficult to teach in block periods.
Less material may be covered.