Monday, 24 January 2011

What we know from science about how to pass your exams

Whether you’re cramming your specialist subject for an appearance on Mastermind, or trying frantically to learn lecture material for an impending exam, there is abundant evidence from cognitive psychology of some strategies that might help.

For many years, researchers considered that the traditional method of simply repeating information over and over to yourself, while improving long-term memory for the information to some degree, was far less effective than so-called “elaborative” processing, which involves relating the to-be-remembered information to other associated facts and previous knowledge. However, new research published this week in Science by Jeffrey Karpicke and colleagues indicates that an even more successful strategy can be to repeatedly test yourself on the information.

Although the merits of so-called “retrieval practice” have been known for some time (see below), the students in Karpicke’s experiment who used the method showed a 50 percent improvement in retention after a week’s delay compared to those who used an elaborative learning strategy – a startling result.  It remains to be seen whether the advantage for Karpicke’s retrieval practice method holds over the longer time-frames that may be relevant for an academic exam schedule, where knowledge might be tested several months after it was initially learned.  However, this finding adds valuable impetus to the notion that active approaches to learning when revising for an upcoming exam can reap dividends for the students who adopt them.

Here is a brief run-down of some of the cognitive psychology evidence suggesting learning strategies that may be effective.  At the end, I'll summarise some top tips to maximise your exam performance.

It is well established that “rehearsing” information (repeating it to yourself, either out loud or sub-vocally) retains it in short-term memory, and increases the likelihood of that information being transferred into long-term memory.  Just ask any actor!  Pirolli & Anderson (1985) asked participants to rehearse sentences and examined the effects of this rehearsal on time taken to recognise the sentences as having been previously encountered.  They found that long-term memory retrieval improved as a direct function of the amount of rehearsal that was undertaken.

Level of Processing
Craik & Lockhart (1972) demonstrated that the level of processing a stimulus receives during encoding has a considerable effect on its memorability.  They asked participants to learn lists of words either using simple repetition or by thinking about the words’ meaning and relating them to associated words and previous knowledge.  The meaning-based encoding processes resulted in much greater recall than did repetition.  Craik & Tulving (1975) went on to confirm that the type, or “depth”, of the processing is important.  They asked participants to learn words (e.g., table) using one of the following tasks: Perceptual – is the word written in capital letters?  Phonological – does the word rhyme with “able”?  Semantic – is the word an item of furniture?  Highest levels of recall were observed following the “deeper” semantic task.

Anderson & Bower (1972) suggested that level of semantic processing may be less important than the extent to which the to-be-remembered information can be related to associated information and previous knowledge.  They asked participants to remember sentences in two conditions: study alone (“The doctor hated the lawyer”) or elaborate (generating a continuation to the sentence, e.g. “The doctor hated the lawyer because of the malpractice suit”).  The elaboration condition improved memory for the sentence, suggesting that participants were more likely to recall the elaboration because they had generated it themselves, which helped them to recall the associated word “lawyer”.

Stein & Bransford (1979) examined whether it is critical for elaborations to be participant-generated.  They compared trials in which participants generated elaborations themselves with trials in which elaborations were provided by the experimenter.  Experimenter elaborations produced better recall than participant-generated elaborations, but only if they were precisely relevant to the sentence content, suggesting that the critical factor is whether elaborations constrain the to-be-recalled information.  Bransford et al. (1979) tested this idea further by asking participants to remember sentences with minimal elaborations (e.g., “A mosquito is like a doctor because they both draw blood”) or multiple elaborations (e.g., “A mosquito is like a raccoon because they both have heads, legs, and jaws”).  Recall was much better for the minimally-elaborated sentences, although most studies show that the more elaboration the better.  Bransford et al. suggested that the nature and degree of precision of elaborations in constraining the to-be-remembered information is key.

Frase (1975) examined how constrained elaboration can be applied to the real-life situation of studying material for exams.  One group of participants were given topics in the form of questions to think about before reading a text, whereas the other group were just asked to study the text.  Frase found that reviewing the text with questions in mind facilitated retention and subsequent recall of the material.  This was particularly the case if the questions were relevant to the material (i.e., helped constrain and guide reading, anchoring new concepts to previous knowledge on the basis of meaning).

Bower et al. (1969) investigated another influence on memory: the degree to which to-be-remembered information is organised.  One group had words to be learned presented to them in an organisational hierarchy, whereas the second group were presented with a similar tree structure, but with the words positioned randomly.  It was found that the organised group had an advantage in retention of the words.  Analysis of the order in which the words were recalled indicated that participants had organised the material according to the tree hierarchy, and thus had a systematic way to go through and cue their memories for the words.

Another factor shown to influence retention is the time over which encoding of information occurs.  Massed practice is when many repeated trials with the same information are undertaken without interruption, whereas spaced practice is when increasing intervals of time are used between repetitions of the same information.  Bahrick (1979) taught participants English-Spanish word-pairs using repeated training sessions that were massed, or separated by 1 or 30 days.  It was found that for long-term retention, spaced study was better than massed, although over the short-term (immediate retention), massed study was optimal.  As mentioned above, this has implications for the results of Karpicke’s study.

Active Retrieval
This is the strategy that Karpicke’s study focused on.  It was Tulving (1967) who was among the first to examine whether manipulating the method of studying material (e.g., elaborative encoding) is the only way to influence retention or whether the act of retrieval itself might affect subsequent memory.  In a number of experiments by Tulving and his colleagues, participants learned lists of words with three conditions: standard (study, test, study, test), repeated study (study, study, study, test), or repeated test (study, test, test, test).  Because the repeated study group had three times as many study exposures to the material as the repeated test group, they should have had better memory if learning occurs only during study trials. But Tulving found equivalent learning across conditions, suggesting that test trials are as effective as further study trials in boosting learning. An extension of this work by Karpicke & Roediger (2006) showed that if retention is measured after a one-week delay, repeated retrieval testing can lead to better recall than repeated studying.

As discussed above, the new research from Karpicke and colleagues published this week takes this forward by indicating that repeated testing of retrieval may be by far the most effective of the strategies discussed here for a student to use when revising in order to improve their performance in an upcoming exam.

To maximise your performance, here are some top tips:

Always revise actively!
  • Process information deeply; don’t just rote memorise
  • Process information elaborately; think about connections between material
  • Organise information into logical structures(e.g., answers to essay questions)
  • Space study sessions as much as possible
  • Trying to retrieve information can be even more important than studying; test yourself repeatedly while learning

If you know of any more effective study strategies, let me know in the comments section.


  1. Or in computer-science-speak, human memory is a store-on-recall system, paradoxical as that may sound. This makes sense if you think of remembering as an active, reconstructive process rather than a simple playback of some abstraction of sensation. has an extremely ugly website with some an interesting approach to exploiting this fact to improve your memory skills.

  2. In my experience, testing and testing does not only make me familiarize my lessons. It also lessens the stress that I feel in studying.