Monday, August 3, 2015

Spaced Practice and Repercussions for Teaching

I've been reading John Hattie's book, Visible Learning, in which he ranks the effect sizes of different strategies that help student achievement. One of the strategies that is pretty high on the list is that it is better to give students spaced (or distributed) practice as opposed to mass practice. In other words, rather than having a student practice something over and over again in one day, it is much better to spread that practice out over multiple days or weeks. (You can read one of these studies here.) The main benefit is that spaced practice helps with long-term retention.

While this research certainly gives some justification for providing students with multiple opportunities to revisit older topics, I am left to wonder if this should change how I structure my lessons and assessments. I, like many others, teach by units. My students might spend a month on fractions followed by a test. They then get a month of algebra followed by another test. We, as teachers, create this span of time when all learning about a particular topic must happen. We don't always give students the time to practice these ideas, particularly the more challenging ones that almost always happen at the end of the unit and right before the test.

Based on what I've read about spaced practice, I would propose that teachers shouldn't give tests at the end of a unit. Perhaps students need time to practice these skills over several weeks before you should assess them. This is something I'm going to explore this year with some of the concepts that were challenging for my students last year.

Note: This is probably not an original idea and I'm sure someone else out there has probably explored it. If you have any resources to share on the subject, I'd greatly appreciate it!

Another note: I do allow my students to retake quizzes which I had hoped would send the message that learning doesn't stop after the quiz is taken. However, very few of my students have taken advantage of this in the past. I am hoping to correct that this year with some ideas from Dylan Wiliam, Ashli Black, and others.

Update: Henri Piccioto has written about this and calls it "lagging homework". He also reinforces the idea that quizzing should happen much later then when the material was taught. Thanks to Mary Bourassa and Chris Robinson for helping me find his work!


  1. I'm interested in hearing how others make this work in their classrooms (if at all). I completely believe in the concept, but I am one of 5 or 6 teachers that teach each course and I am not sure I can get them all on board - and since we give common assessments, I'm not sure I could just stretch out my timeline and not everyone else's.

    1. Yeah, at my school we all lagged homework and assessments, so it worked out.

    2. I teach one course with only one other person, perhaps I can get her on board.

  2. Also see the posts I linked to at the bottom of the Lagging Homework post: the other ingredients are delayed quizzes, quiz corrections as homework for points, and separation of related topics.

  3. Note that the lagging strategy does not invalidate a unit structure for a course: it merely reorganizes it. (Though if you teach in the long period -- or block schedule-- I recommend working on two units at any one time.)

  4. I've been reading Make It Stick this summer. The authors extol the value of mixed and spaced practice as well. The handful of times I tried spaced practice and lagging assignments last year, I typically had higher completion and accuracy rates for my classes. I look forward to trying spaced practice this year, too. I'm not sure how it will look. Dylan Kane wrote about writing short mixed practice assignments for his classes and someone else I'm forgetting mentioned assigning the same problem number from multiple sections of a textbook.