Learn in a Burst or Learn Slowly?

Say you want to learn French. Would you do better if you studied for 100 hours in a year-long course (~2 hours per week) or if those hours were compressed into a month (~20 hours per week)?

Surprisingly, the answer seems to be that more intensive language education programs do better! This appears to be a fairly consistent research finding, in the dozen or so studies where the comparison has been made. From a paper by Raquel Serrano and Carmen Muñoz:

[We] analyze the performance of adult students enrolled in three different types of EFL programs in which the distribution of time varies. The first one, called ‘extensive’, distributes a total of 110 h in 7 months … ‘semi-intensive’, which offers the same number of hours distributed in 3–4 months … intensive course offers 110 h in 5 weeks … The results from our analyses suggest that concentrating the hours of English instruction in shorter periods of time is more beneficial for the students’ learning than distributing them in many months.

The research is surprising because the spacing effect is one of psychology’s most robustly replicated effects. Essentially, when material is presented repeatedly, spread out over time, it results in enhanced memory compared to repeated presentations in short succession.

What’s Going on Here?

When I stumbled into this research a couple weeks ago, it surprised me! If any research result felt solid, it was the spacing effect. While the spacing effect and the…