Memory is a fascinating thing. Essentially, the more we replay something that has happened to us in our mind, the stronger the chance that it will move into the long-term memory, and thus be remembered for some time. The replaying can take many forms. It may be someone asks you a question about your day, a question about something they know you heard on the news, or simply you sitting on the train on your way home going over an incident that really annoyed you. All of these retrievals of the already happened moments strengthen the memory of them. However, the strength of the memory is related to how much work you have to do to replay it. If you merely think about it, the memory won’t be as strong as if you had to tell someone about it (Roediger and Karpicke, 2006).
This theory of retrieval has enormous implications for education.
If you want students’ memory of key concepts to improve, provide opportunities for them to retrieve that content. One of the most efficient ways of doing this is to ‘test’ student knowledge using low stakes assessment. This can be done formatively by asking questions and by getting students to write down or represent what they know. This process has several benefits:
- It helps you to see what students do or don’t know, which means you can adjust your learning sequences if necessary to correct misconceptions
- It helps students strengthen the neural pathways the information flows in which makes remembering the information easier at a later stage.
- The ease of remembering frees the working memory for new information to be encoded more efficiently
In 1913, Ebbinghaus came to the conclusion that when learning something new, ‘With any considerable number of repetitions a suitable distribution of them over a space of time is decidedly more advantageous than the massing of them at a single time.‘ The theory came to light after he realised that we begin to forget information as soon as we encode it. The ‘forgetting curve’ demonstrates this aptly. When Ebbinghaus interrupted the forgetting by retrieving the information at certain points, he could consequently ‘remember’ the information at a later date.
So, interrupting the forgetting curve by including retrieval into your sequence of learning is paramount. But the timing of that interruption matters. Bjork suggests that if you have students retrieving information too soon after encoding the effects on memory are weak (high retrieval strength but low storage strength), but if you wait too long, the information may need to actually be retaught. Joe Kirby explains this well here. There seems to be a sweet spot in terms of timing the retrieval practice. Of course, students will vary in what that timing should be, depending on various factors, including what their attentiveness was like when first presented with the content. However, effective teaching will realise that students invariably need access to information on at least 3 occasions for it to have a chance of being converted into the long term memory (Nuthall), and so continuously returning to previously taught content by weaving it into the current learning is a must.
As already stated, this HOW of delivering retrieval is pertinent. What is ideal is to create a situation that is not too easy, quite challenging, yet no too hard. Bjork alludes to this notion when he discusses ‘desirable difficulties’, where the testing makes the activity ‘desirable because it can trigger encoding and retrieval processes that support learning, comprehension, and remembering.’
What is important however, like in all learning design, is to ascertain where students are on the learning continuum before creating the retrieval: ‘If, however, the learner does not have the background knowledge or skills to respond to them successfully, they become undesirable difficulties.’ This insight rationalises why simply re-reading notes or a textbook has been consistently found to be significantly less impactful on learning than actively demanding a response from a student.
Engaging students in having to actively retell what they know can take several forms, including completing a concept map about a topic, writing down everything one knows about an idea, or answering questions about the content. The really useful Retrievalpractice.org has a host of ways to enact the strategy here. It’s a practice that shouldn’t be bound by sector, or discipline, and in fact should be implemented as soon as learning begins, as some primary teachers are now demonstrating.
But perhaps the most effective form of retrieval practice is the test, where students have to search their memories to produce answers. The next post discusses the power of the online multiple choice test.
I’m Paul Moss. I’m a learning designer. Follow me @edmerger