Following three years of extensive research and discussion, Skyline High School in Longmont, Colorado, some 35 miles north of Denver, scrapped its traditional semester calendar for a new structure. The alternative schedule—a trimester system—has proven to be uncommonly successful for students, teachers, administrators, and parents alike. We enjoy fewer and longer classes each day, impressively reduced class sizes, and more free time for teachers and flexibility for students, all of which have translated into improved student achievement.
We first instituted the 5 × 70 trimester schedule, as we call it, in the 1993–94 school year. It represents a real departure from our traditional system of two 18-week semesters, or four quarters. The school year is now divided into three 12-week grading periods, which correspond to the fall, winter, and spring seasons. The school day is divided into five class periods of 70 minutes each, in contrast to the previous seven-period day, with 50 minute classes. There are shorter breaks between periods—five minutes instead of 10, but a longer lunch hour—50 minutes instead of 30. In addition, we now have one common lunch hour for all students, whereas before students were divided between two lunch periods.
Most core courses are given over two trimesters. So-called year courses, which formerly took two semesters, now extend over three trimesters. These include the Advanced Placement courses, all upper-level science classes, and several choral classes, as well as band and jazz band. Freshmen and sophomores are required to register for five classes each trimester, whereas juniors and seniors are allowed what we call time release, provided they are on track for graduation.
Better Students
As Figure 1 shows, grades have generally improved since the change went into effect. Although there was an almost 1 percent decrease in the number of As, there was almost a full 1.8 percent decrease in the number of Fs. We attribute this welcome improvement to a number of factors.
Figure 1. Grade Distribution: A Comparison
A Colorado School's Un-Rocky Road to Trimesters-table
1992–93 (Semesters) | 1993–94 (Trimesters) | Change | |
|---|---|---|---|
| A | 30 | 29.1 | -0.9 |
| B | 23.4 | 23.8 | 0.4 |
| C | 19 | 23.8 | 4.8 |
| D | 10 | 10.6 | 0.6 |
| F | 9.3 | 7.5 | -1.8 |
| Note: The figures in the 1992–93 column represent an average of each grade given for the four quarters (two semesters) that year. The figures in the 1993–94 column represent an average of each grade given for the three grading periods that year. |
First, because each section has fewer students (about 24 compared to about 29 before), teachers can personalize instruction more than they could in the past. Teachers also have more time for active student engagement, in the form of laboratories, small groups, presentations, and so on. According to teacher surveys we conducted after the first and third trimesters of the 1993–94 school year, science teachers can now complete laboratories in one class period. Interestingly, science and math instructors, in particular, have discovered that they are actually covering more material in one trimester than they did in one semester.
Because students have fewer sections each day, they tend to be much more focused than they had been under the semester system. And, as one language arts teacher said, the added time enables students to complete tasks that require particular concentration. In addition, students previously could fail the first or third quarter and know full well that they could still pass the semester by working harder the second or fourth quarter. They now know, however, that the trimester offers much less leeway for slacking off. As a result, teachers say, students tend to be more diligent and determined to succeed.
Among the advantages for students is the much greater flexibility that trimesters afford. More courses and sections are offered. And the social studies department, for example, allows students to take most of its classes in any order over the trimesters. Thus, a student could elect to take Civics B the first trimester and Civics A the second or third. Further, with one additional grading period each year, students who fail a trimester of a two-trimester course may repeat the course and still remain even with other students in their grade.
Students also have an opportunity to earn more credits overall. They can earn 7.5 credits per year, or a total of 30 credits for four years, as opposed to 7 credits a year and a total of 28 under the semester system. (Even though each class period is now 20 minutes longer, it is still worth .5 credits. Accordingly, a two-trimester class results in 1 credit, and a three-trimester class in 1.5 credits.)
Not least of all, students have enjoyed the longer lunch hour. They can leave campus in a leisurely fashion and return in ample time for the afternoon classes.
More Satisfied Teachers
As for teachers, they report that their days are less hectic and tiring. Everyone except physical education teachers has fewer total students—most fewer than 100 each day. And with only four classes a day rather than five, teachers generally spend less time on classroom preparation. Yet they have one longer 70-minute preparation period and a duty-free, 50-minute lunch hour, whereas they previously had only 50 minutes for preparation and a 50-minute supervisory period.
This means that each day teachers have at their disposal a full two hours of unassigned time, 50 percent more than they used to have. Many teachers have found they can productively use the extra time to collaborate with colleagues in and out of their own departments.
Appreciative Administrators
Our four administrators, too, have been pleased with the new schedule; we are particularly heartened by signs of academic improvement.
The ability to assign teachers to more classes without stretching the staff too thin or increasing the number of full-time teachers is a boon for any principal. (With four classes a day per trimester, teachers now teach 12 sections a year rather than 10, but this is not considered an increase in the Full-Time Equivalency.) As the assistant principal (and an administrator for 25 years), I have never found it so easy to adjust students' schedules.
It also simplifies administration when class changes take place only three times a year instead of four. And because all sports seasons now correlate with the trimesters, it's much easier to determine students' eligibility for athletic teams. The trimester system also simplifies life for counselors. As one counselor commented, “There were fewer changes to be made and less confusion.”
There is, in addition, a calmer, less hectic atmosphere in the building as a whole. The fewer and shorter class breaks make for less disruption (and less trash as well), as does the one common lunch hour. (I personally appreciate having only one lunch hour to supervise.) Finally, parents' interest in the new schedule has carried over into their increased involvement in the life of the school.
The Right Choice
In the three years we researched and analyzed the schedule, we considered many alternative approaches. We looked at the plan another high school in our district had adopted a year earlier—the so-called block schedule, featuring four 90-minute periods a day, with year-long classes compressed into a semester. We considered macro-block scheduling, the type favored in the Copernican Plan that a number of schools across the country have implemented. In the end, we concluded that the trimester plan would deliver the most advantages with the fewest disadvantages.
In retrospect, we would offer more teacher training before instituting the new schedule. When making a change of this magnitude, it is critical to give teachers an opportunity to plan for and adjust to the new routine. Although our teachers did participate in some informal staff development sessions, they could have used even more.
In the end, though, we were fortunate to have made the right decision. Everyone involved is now benefiting—indeed, prospering—from the change.
