The vital important of timing - for teachers and lecturers
Learning is not just about content, but also about timing. Image via Pixabay
It’s important that our students remember what we teach them. That is why we do it, right?
I bet you give some talks, classes or lectures where you explain your material really well. You have nice slides, you give an eloquent and passionate account of the material, and most of it is pretty interesting. The thing is – how much will your learners remember in a few weeks time?
The psychology of human memory can help us to answer this question. We know several key things about forgetting:
It progresses very rapidly.
Abstract information and specific details are forgotten more rapidly than meaningful information and gist.
Consolidation is very important if learning is to last over the long term – and so is the timing of this consolidation.
Learners and teachers alike tend to misjudge many aspects of how memory works. It is not intuitive.
Let’s consider each of these four issues in turn.
Forgetting is fast
A classic finding in experimental psychology – dating back over one hundred years – is the forgetting curve. This shows that forgetting moves quickly at first, and then slows down. Most of the forgetting that takes place is likely to happen in the first few hours or days.
However, at the very beginning – during or straight after your class or lecture – learners still remember quite a lot. They may not even perceive that forgetting is happening. And for that reason, they may fail to do anything about it.
The good news is that if learners still remember information and ideas after a few weeks, they will probably also remember it months later – at the time of their exam, for example.
But the bad news is that they won’t remember all that much by that point if they have failed to do any consolidation. This means that when it comes to their exam revision, they will be starting from scratch in some areas. They may not even remember having heard the information in their notes.
Details are lost more quickly than gist
A complicating factor is that not all types of information are forgotten at the same speed.
You may have the experience of hearing an anecdote and joke, and then trying to remember or re-tell it the following day. What do you remember? Probably you do remember the overall point, they key ideas or punchline, but what you retrieve from memory will not be word-for-word identical to what you originally heard. You remembered the gist but not the details.
It’s the same for your students. They will remember key meaningful ideas quite well, but forget the details (unless they take some effective action to retain those – more on that next). And this makes it more likely that their memories will be distorted, and that misconceptions about the material will take hold.
Well-timed consolidation IS IMPORTANT
You might be thinking at this point that every teacher should ensure that they repeat what they have said very soon – perhaps the very next day, or even say it several times within the same lecture to stave off forgetting.
But that wouldn’t actually help very much.
If things are rapidly repeated, the forgetting still proceeds rapidly from that point on. It’s like cramming for a test – it’s helpful in the short-term, but the information is still likely to be forgotten over a longer timescale.
What would help would be to time consolidation better – delaying each repetition until the material was on the point of being forgotten.
The spacing effect is a well-documented effect in human memory. It shows that practice which is delayed and spaced out over time is more effective than intensive practice. A delayed practice session can be twice as effective, and practice which comes very soon – immediately after initial learning – can sometimes have almost no effect at all (Dempster, 1988).
Consider some practical examples of this:
If you are practicing a musical piece three times, it would be better to do this on three separate days than three times on the same day.
When re-reading information, it would have more of an effect to do this after a delay (when the information has been almost forgotten) than immediately after reading it the first time (an exception is if you didn’t understand it the first time, in which case re-reading the text soon would be useful).
It would be better to split a long study session into two or more parts, rather than trying to take everything in in a single day.
If a student is running through some flashcards, testing themselves on a key topic for their course, it would be best to repeat the flashcards a week later (at least, once they are starting to get the answers right) rather than straight away.
What all of these examples show is that a delayed review is more effective than intensive practice. Spacing works. However, learners often fail to realise this! Which leads us on to the final issue:
Learners and teachers alike tend to misjudge forgetting
This is well demonstrated by a classic experiment by Eugene Zechmeister and John Shaughnessy, entitled ‘When you know that you know and when you think that you know but you don’t.’
In the study, college students were shown words twice, with the repetition coming either straight away (‘massed’) or after a delay (‘distributed’). The distributed condition led to better recall, but most students incorrectly believed that they were more likely to remember words that had been repeated in a massed fashion (Zechmeister & Shaughnessy, 1980).
This error is found in the world outside of the psychology lab, too. In a large-scale survey, 56% of university students reported studying “whatever is due soonest”, and only 23% reported returning to review material after a course/module had ended. 53% said that they did most of their study in a single session before a test/exam. These findings showed that flawed ideas about effective spacing of one’s learning are widespread – and the researchers also found that these flawed habits were linked to lower grade point averages (Hartwig & Dunlosky, 2012). Poor judgement of learning and forgetting can have a real effect on how well students do at school and university.
Some practical suggestions
What can we do to build in more effective consolidation in lectures and seminars? Here are some practical suggestions:
If you give a lecture once per week, begin the lecture with review questions. To make good use of time, these could be displayed during the period when students are still arriving in the room.
Break lectures up with further review questions based on the new material, for example by asking them about something 10 or 15 minutes after you explained it. Even such a short delay is useful for new learning, and the breaks will also to boost concentration, which often flags mid-way through a lecture.
Make clear links back to older topics. Ideally these will prompt learners to actively think about and recall what they learned previously, rather than being (passively) told the information again.
Longer topics could be offset across weeks, rather than covering a single topic in one week. For example, when I am teaching theories of learning, we spend the first 30 minutes or so of a seminar reviewing and consolidating the previous week’s topic, before moving on to the new topic.
Homework, review sessions, assignments, and tutorials could likewise be offset, practicing material from a previous week rather than working on what was covered most recently. For example, of you give a lecture on DNA in the first week of your course, you could set a tutorial task on that topic to take place not in week 1 but in week 3 or 4.
In classes and tutorials, set tasks that don’t just practice new material but integrate older material too. This could involve asking students to comment on the similarities and differences between the current topic and the previous one, or to do an applied project task that draws on several topics.
Review things more than once. Provided that the material has been well understood, two short reviews will be more effective than one long one (because you are in effect spacing out the second half of the review; in contrast, continuing to practise beyond the point of mastery (‘overlearning’) is ineffective (Roher & Taylor, 2006).
Guide students towards using more effective study habits in their independent study (see this post with more details on how to study effectively, as well as the flawed strategies that should be avoided). Flawed beliefs about learning and forgetting mean that most learners will not adopt these strategies spontaneously.
Such changes can make a real difference. And the great thing about applying the spacing effect to your teaching and lecturing is that it can have a large effect without requiring much of a change. Your materials and teaching can stay much the same – all that changes is the timing.
Do remember, however, that learners may not intuitively see the benefit of delays. It is worth taking the time to explain to them that while delayed practice and review questions are challenging, they will help them to retain the material effectively over the long term.
Good luck, and happy scheduling!
For more on applying the spacing effect to all aspects of classroom teaching, see my book Psychology in the Classroom, especially chapter 1.
For more on effective study habits, my short guide How to Learn is aimed at school and early university students, and covers studying, note-taking, revision and much more.
References
Dempster, F. N. (1988). The spacing effect: A case study in the failure to apply the results of psychological research. American Psychologist, 43(8), 627-634.
Rohrer, D., & Taylor, K. (2006). The effects of overlearning and distributed practise on the retention of mathematics knowledge. Applied Cognitive Psychology: The Official Journal of the Society for Applied Research in Memory and Cognition, 20(9), 1209-1224.
Zechmeister, E. B., & Shaughnessy, J. J. (1980). When you know that you know and when you think that you know but you don’t. Bulletin of the Psychonomic Society, 15(1), 41-44.