Seven Study Techniques and the Time Each One Costs

A technique that works but takes three hours is a different proposition from one that works in ten minutes, especially in a week with two deadlines and a lab report. Below are seven techniques with the time each one costs, including one that is not worth it for most students.

The times are rough estimates from ordinary coursework. No study measured them, so treat them as a way to compare the techniques with each other.

1. Closed-book recall

1. Close your notes.
2. Write down everything you can about one topic.
3. Open your notes and mark what was missing or wrong.

Cost: five to fifteen minutes per topic.

In Roediger and Karpicke's experiment, re-reading a passage gave slightly better recall on a test five minutes later. A week later, a passage the students had practised recalling was remembered better: 56% of it, against 42% for a re-read passage.

Dunlosky and colleagues' review of ten study techniques rated practice testing as one of the two most useful. Few students do it: in one survey, 11% said they tested themselves, against 84% who re-read. There is more on how to do it in active recall vs re-reading.

2. Spacing the same topic across days

Rather than doing ninety minutes on one topic tonight, do thirty tonight, thirty on Thursday and thirty next week.

Cost: no extra study time. The cost is planning: something has to keep track of what comes back and when.

In a large study by Cepeda and colleagues, spacing a review out gave roughly double the recall on a test ten weeks later compared with reviewing straight away, for the same study time.

A spaced repetition planner can lay out which topic to review on which day. In SymbioLearn, Today names the Concepts in a Module that deserve attention and gives a plain reason for each, such as how long it has been or where you have been caught out. What you then do with them is up to you.

3. Past papers under exam conditions

Sit a whole paper, timed and without notes, then mark it against the mark scheme as strictly as an examiner would.

Cost: the length of the paper plus roughly as long again to mark it. Three hours is a realistic afternoon, the most time any technique here takes in one sitting.

It is worth it in the last two or three weeks, because it practises things the other techniques do not: reading the question properly, budgeting time across sections, and writing clearly at speed while tired.

Earlier in the term, you will not have covered enough for a full paper to be much use. Single questions on the topics you have covered are a cheaper way in.

Mark it properly. Sitting a paper is recall practice in itself, but the marking is where you find out which answers lost marks and why.

4. Interleaving problem types

Instead of twenty questions on integration by parts, do a mixed set where you have to work out which method each question needs.

Cost: no extra time, but expect to get more wrong during practice than you would in a set of one type.

In Rohrer and Taylor's study, college students learning to find the volumes of different solids did better during practice when the problems were grouped by type. A week later, the students who had practised mixed sets did far better on the test. It can also fool you: in a study where people learned to recognise painters' styles, participants rated grouped practice as more effective even after their own test scores had shown the opposite (Kornell and Bjork).

The reason is that in the exam, nothing tells you which method a question needs. Grouped practice lets you apply a method you have already been handed. Mixed practice also makes you choose it.

The evidence is strongest in maths. Dunlosky and colleagues rated interleaving moderate utility: the maths results are large, but the research overall is small and includes some studies that found no benefit. Start a new method with a few problems of one type, then mix it in with the types you already know.

5. Asking why after each claim

Read a line, then answer two questions before moving on: why is this true, and what would be different if it were false? This is called elaborative interrogation.

Cost: adds roughly half again to your reading time. A chapter that took forty minutes takes an hour.

Use it where the content has reasons in it, such as how a tax changes prices in economics or why a legal rule exists. Skip it for arbitrary facts, vocabulary and notation, where there is no reason to find.

It works best when you already know something about the topic. In one study described in Dunlosky and colleagues' review, Canadian and German students learned facts about Canadian provinces and German states, and asking why helped more with the facts about their own country (a 24% gain against 12%). The review rated it moderate utility, partly because most of the research used short lists of facts rather than long, complex texts.

6. Explaining one topic aloud without notes

Talk through a topic as if to a classmate who took the same prerequisites and missed the lecture.

Cost: ten to twenty minutes per topic, and somewhere you can talk without an audience.

This overlaps with closed-book recall, but it is especially good at showing where your understanding of a process breaks down. In studies by Rozenblit and Keil, people rated how well they understood everyday devices such as zips and flush toilets. After writing step-by-step explanations of how they work, they rated their understanding lower.

Stop at each point where you cannot finish a sentence or explain how one step leads to the next, and write it down to study rather than pushing through.

7. Rewriting notes into a clean study guide

Take messy lecture notes and produce a neat, formatted, colour-coded version.

Cost: hours per topic, the largest total on this list.

This is the one to drop. Copying notes out neatly is mostly reading: at no point do you have to produce anything from memory. It is also common. In the survey above, 30% of students listed rewriting their notes as a strategy. The nearest techniques in Dunlosky and colleagues' review, re-reading and summarising, were both rated low utility.

There is one narrow exception. If your notes are genuinely unusable, converting them once is reasonable. Convert them into questions rather than prose, and you are doing technique one with a tidying step attached. A beautiful study guide that you then re-read is not worth the hours.

What to do next

1. Pick one topic from this week.
2. Tonight, do closed-book recall on it (technique 1).
3. Put two more recall attempts on the same topic in your calendar: one in two days and one in a week (technique 2).
4. In two weeks, try to write the topic out from memory. That tells you whether it is working.

If you would rather not track the spacing yourself, Today in a SymbioLearn Module lists the Concepts worth coming back to, based on what you have actually done with each one.