The forgetting curve: Interleaving vs Blocking


The audience for this post is my students. I have written it so I can give this to them on the first day. I might also make a PPT for this which includes the videos. 

Learning how to learn

You’ve been in school for a while now, but how often have you thought about how you learn? Since learning is an activity which will take up most of your time, particularly in your final years of schooling and university beyond, you’d better be good at the actual art of learning. The good news is that you can learn how to learn. The sooner you get better at learning, the sooner you will reap the rewards. So, what should you do?

You should become aware of metacognition, you need to know about ‘distributed practice‘ or ‘interleaving‘ and you must know how your brain acquires and retains information.

Let’s start with metacognition, which is the most important. In it’s simplest form, metacognition is thinking about thinking. 

  • Metacognition refers to one’s knowledge concerning one’s own cognitive processes or anything related to them, e.g., the learning-relevant properties of information or data. For example, I am engaging in metacognition if I notice that I am having more trouble learning A than B; if it strikes me that I should double check C before accepting it as fact. (Flavell, 1976)
  • Metacognition: awareness or analysis of one’s own learning or thinking processes. (Merriam-Webster, 2012)
  • Metacognition also includes self-regulation—the ability to orchestrate one’s learning: to plan, monitor success, and correct errors when appropriate—all necessary for effective intentional learning… Metacognition also refers to the ability to reflect on one’s own performance. (National Research Council, 2000)
  • Students learn to monitor and direct their own progress, asking questions such as “What am I doing now?,” “Is it getting me anywhere?,” “What else could I be doing instead?” This general metacognitive level helps students avoid persevering in unproductive approaches… (Perkins and Salomon, 1989)

Metacognition represents more than just study skills, it has been linked to improving your thinking skills and promoting conceptual understanding. a  There is also evidence that improved metacognition is associated with overall academic success and that students with poor metacognitive skills perform less well academically than peers. b

There is a lot of research about how to learn most effectively, but the concept that is currently seen as one of the most effective ways to learn is called ‘distributed practice’ or ‘interleaving’ or ‘spaced practice’.

Interleaving vs Blocking

‘Blocking’ the learning of new knowledge seems to make sense. First you learn A, then B, then C. So your learning might look something like this: AAA BBB CCC; You start with the first topic or skill, learn all about it, then move on to the next topic or skill. A lot of research shows that while this is the most common form of learning in schools, it is not actually the most effective way in which to learn. Research shows that the brain retains information better when that new information is mixed up with older information, when it is ‘interleaved’ c Another way to describe ‘interleaving’ is ‘distributed practice’ or ‘spaced practice vs mass practice’. When you interleave, your learning pattern might look like this: ABC ABC ABC, rather than the blocked AAA BBB CCC.

This excellent infographic explains how spaced / distributed repetition of new knowledge aids retention: (Click on image for larger version)Memory-Retention-and-the-Forgetting-Curve-Infographic

This video below explains the biological side of learning. Can you see how this particular video also ties in with the idea of ‘distributed practice’?


CaptureTiramisu Learning

Finally, you could see interleaved or distributed practice as a perfect Tiramisu cake. The cake will only be delicious if there are many layers. The layers work together and the end result is an A grade cake. It’s the same with learning, you need to have lots of layers of exposure to the same information (ingredients) to make a perfect cake.
(‘Tiramisu learning’ is a patented teaching technique, developed by Ms Liversidge!)

The forgetting curve

So here is the forgetting curve again, it’s the line in blue. Incorporate ‘interleaving’ (repeated review sessions) in to your study sessions so that you retain significant information. Be ‘metacognisant’.forgetting curve

More reading:

  1. The Teaching of Thinking
    By R. S. Nickerson, D. N. Perkins, E. E. Smith  (back)
  2. Tanner, K. D. 2012. “Promoting Student Metacognition”. Cell Biology Education 11 (2): 113-120. American Society for Cell Biology (ASCB). doi:10.1187/cbe.12-03-0033. Accessed: 10/12/15  (back)
  3. Pan, Steven. 2015. “The Interleaving Effect: Mixing It Up Boosts Learning”. Scientific American. Accessed December 21 2015.  (back)