Roche Limit

Shovelling It In

It is easy, under the pressure of exams, to focus on revising the material as easily and quickly as possible. Creating and reading through summaries can give you that warm feeling of having made rapid progress. You copied key points from your textbook yesterday, and reading through your notes it all looks familiar and you feel that it has been learned. You go into class and your teacher reviews what was covered last lesson, and you recognise all that is said. You become more confident that you are done, that reading through your notes again before the exam will get you through comfortably. But the exam doesn't go well, so next time you work harder, write more notes, listen more carefully to the teacher in the reviews. You work harder and harder, but the grade improvements don't come. What is going wrong?

The problem is that the students efforts are being directed towards inefficient methods. Practising the shovelling in of knowledge does not effectively improve your ability to retrieve that knowledge on demand. Working hard on giving yourself opportunities to recognise what you read only serves to verify that you have learned something, when what is needed is to develop the ability to recall that something when it is needed. Developing this different skill needs a different approach.

Short and Long Term Memory

There are two forms of memory important here, and two processes for each. There is long term memory, and short term memory, and for each memory there is a storage strength and a retrieval strength. The main errors made by learners, and their teachers, is to rely on tasks that focus either on retrieval from short term memory or on developing memory storage strength, when the target is to improve the retrieval strength of long term memories.

Common activities in classrooms, such as end of lesson quizzes or the banks of similar problems as is common in Mathematics lessons, can rely more on short term than long term memories. Once you have done the first exercise,and have recalled the strategy that was taught a few moments ago, you just have to do the same thing throughout the whole exercise until you reach the end of the page. There is little need to draw on long term memories in this type of task, so the skills practised will often fade rapidly after the lesson has ended.

Similarly, reading or recognition based tasks, such as reviewing notes or completing multiple choice questions where all the answers are there in front of you, focus on the storage strength of the memories instead of developing the ability to retrieve that same information or strategy. This type of activity can feel rewarding at the time if you recognise the material, but there better ways to ensure that you can perform well when you need to draw on that knowledge.

Focussing of Retrieving from Long Term Memory

There are two aspects to remembering: if you want to be able to recall memories, then you need to specifically practice retrieving them, at the same time as ensuring you are retrieving them from long term storage and not the transient short term working memory in which you hold disposable knowledge. If you practise retrieval immediately after learning or reviewing material than you will slow down the progress of that information into easily available long term memories. Similarly, reading the information you want to be able to recall is not very effective at developing your ability to remember things when the written material is not available to you.

Strategies

There are three simple strategies that all teachers and students should be aware of: retrieval practice, spacing, and interleaving. The first emphasises the retrieval over the storage aspects of the memory, while the others focus on accessing long term rather than short term storage.

Retrieval Practice

An example will help here. Imagine you are the teacher starting a lesson which builds on a concept from a lesson last week. You believe, correctly, that the students will not yet have a strong recollection of the material, so to help them along you spend the first few minutes recapping the key points from that lesson, then move onto today's extensions. What has happened in the students' heads? They have listened carefully, perhaps, but it is the teacher that has practised the retrieval of the ideas, not the students. They have passively checked that they have some stored memories of what you have described. It might improve the storage strength of those memories, but they are unlikely to have improved their abilities to recall that material on demand in the future.

A simple switch by the teacher from a recap to a recall practice exercise significantly improves the essential recall strengths of the memories. This can be as simple as a brain dump (“Everyone, in two minutes write everything you can remember about ...”), or a think-pair-share task with three short questions (“OK, without looking at your notes, write the answers, then discuss with your neighbour.”), or a pre-prepared short online quiz. That's it. Students can do it themselves at home, and even flash-cards can work well with this strategy, as long as they write the answers, or say it out loud, before turning the card over to check. Too many people read the front of the flash-card, then turn it over to check their hunch that they knew the answer, but without practising the recall process before reading the answer defeats the purpose of the exercise.

The key is to declare an answer from memory before checking you're right. That practice then instant feedback cycle has been shown to be very effective at developing the recall strength of memories.

Spacing

Practising the recalling skill right after learning something has benefits, but since you are recalling from short term memory you are not developing the recall strength of the long term memory of that item. You need to allow the idea to fade from short term storage, then any recollection you do will be from the long term storage and it will be strengthened by the process.

A simple strategy is to give a class a test on last week's content, instead of what they have just learned. Or test this lesson's work, but always include a question or two from an earlier topic. Doing some recall practice tasks at the end of the lesson students learned will be improved by delaying it until the start of the next lesson. And so on. It should be no surprise that practising the retrieval of memories improves that ability over time, but sadly many students and teachers are keen on sticking to the traditional approaches that have been transmitted to teachers from their student experiences without modification.

Interleaving

When you have a series of near identical problems to solve, especially common in STEM courses, after you have recalled a strategy for question 1, question 2 them becomes a case of simply retrieving from short term memory what you did a moment ago. It would be more effective if you can force the retrieval from long term storage for every question, and this can be done by interleaving questions with even slightly different demands into the one exercise. So, for example, instead of having twenty questions on dividing fractions, mix in questions on adding or multiplying fractions so the student has to select a different strategy each time instead of just doing the same as last time. The key is to enforce the retrieval of a strategy or fact each time, so that the practised recollection is happening from long term rather than short term memories.

Improving Student Progress Through Picking the Low Hanging Fruit

Every teacher should be aware of these strategies and be using them every day in the classroom or lecture hall. Even if they are not, we should be teaching them to the students so they can make better use of their time. Some will want to do the easy thing of continuing with the comfortable and familiar processes they have used somewhat successfully for years. But others can really benefit from making more efficient use of their, or their students', time. These modifications to the practice of learning are simple and can be incorporated easily into most schemes of work and lessons, and into private revision schedules.