picture of school kids and calendars

In the 1990s, school reformers hailed block scheduling (modular scheduling), claiming that it created a framework for more in-depth study in the classroom which aided student achievement. As increasing numbers of schools began adopting block scheduling, however, the move to leave traditional scheduling came under fire. A decade later, the debate is still going strong.

What is block scheduling?

Traditional school schedules consisted of six to eight period schedules, generally 40 to 50 minutes each. In contrast, a block schedule is made up of three to four longer periods a day. There are a number of different forms of block scheduling, but the most common types are:

Alternate-day schedule (or the A/B plan) – classes meet every other day for lengthy time periods rather than meeting every day for shorter periods. Students take eight classes spread out over a year.

4×4 block – each semester, students take four classes (ranging from 85-100 minutes), for a total of eight classes a year.

Other types of formats include the intensive block and the parallel plan. Some schools just build their own block schedule, where they combine approaches.

Pros and cons of using block scheduling

Opinions about block scheduling range from the enthusiastic to the irate. Below is a list of some of the advantages and disadvantages of using block scheduling.


  • Schools with block scheduling report fewer failing grades, dropout rates and discipline problems
  • More time for student-teacher interaction
  • Less time wasted in hallways and opening/closing classes
  • Students can learn a subject in greater depth
  • Students are exposed to a variety of instructional techniques
  • Students have less information to absorb, less homework to complete
  • Students can use their longer lunch blocks to participate in extra-curricular activities
  • Teachers encounter fewer students each day, teach fewer classes each day and have longer prep periods
  • Teachers are able to use a variety of instructional techniques


  • Longer time gaps between instruction and standardized exams
  • Student absences are difficult to make up
  • Teachers have not been trained to engage students for long periods of time
  • Subjects requiring regular repetition (e.g. math, foreign languages, music, etc.) are difficult to teach in this format
  • Lose continuity between classes if do not meet daily
  • Since block scheduling is relatively new to education, there is little research done on the subject and most of what is available is anecdotal.