What Cognitive Science Says About Effective Memory and Recall Techniques

Students and professionals looking to remember more and forget less have access to a large body of experimental research on learning. The most cited synthesis of this evidence is a 2013 review in Psychological Science in the Public Interest by psychologist John Dunlosky and colleagues, which rated ten common study techniques by how well they are supported by controlled experiments.

Techniques rated 'high utility' in the research review

According to the review, summarised for teachers by Dunlosky in American Educator, two techniques received the highest utility rating: practice testing and distributed practice. Practice testing means retrieving information from memory, for example with flashcards or self-made quiz questions, rather than simply looking answers up. Distributed (or spaced) practice means spreading study sessions across days or weeks instead of concentrating them into one long session, commonly called cramming.

The review states that both techniques work for learners of different ages and ability levels and have improved performance across many subjects and even in classroom settings, not just laboratory tasks.

Why self-testing outperforms rereading over time

The effect of self-testing on long-term memory, often called the testing effect, was documented in an influential 2006 study by Henry Roediger and Jeffrey Karpicke of Washington University in St. Louis, published in Perspectives on Psychological Science. Participants either reread a passage four times or read it once and then recalled it from memory three times. Immediately afterward, the group that reread the material performed better. Two days later the two groups performed about the same. One week later, the group that had practiced retrieval remembered substantially more than the group that had only reread the passage.

The researchers concluded that repeated studying produces a short-term advantage, but repeated retrieval produces the more durable, long-term advantage — the opposite of what most students expect, since rereading feels more fluent while it is happening.

Techniques rated 'moderate' or 'low' utility

The Dunlosky review rated interleaved practice, elaborative interrogation, and self-explanation as moderate utility. Interleaving means mixing different topics or problem types within one study session instead of finishing one topic before starting another. Elaborative interrogation means asking oneself why and how a stated fact is true, and self-explanation means describing, in one's own words, how new information connects to what is already known.

Rereading, highlighting or underlining text, summarization, the keyword mnemonic, and imagery for text learning were rated low utility. The review notes that rereading is one of the most common study strategies among students despite showing inconsistent effects on learning outcomes, and that highlighting has generally failed to improve performance in controlled studies.

Elaboration, dual coding and concrete examples

The Learning Scientists, a group of cognitive psychologists who translate memory research for students and teachers, group six strategies together as complementary tools: spacing, retrieval practice, elaboration, interleaving, concrete examples, and dual coding. Dual coding means pairing verbal information with a visual format, such as a diagram or sketch, on the idea that combining both formats creates more ways to retrieve the information later. Concrete examples means attaching a specific instance to an abstract concept, which the group states has been linked to higher test scores in classroom studies.

The Learning Scientists describe spacing as determining when to study, while the other strategies determine how to study, and they note that combining strategies — for instance, explaining a concept from memory rather than from an open textbook — should in theory maximise learning, although they also note that few studies have directly compared combined strategies against techniques used in isolation.

Limits and caveats researchers point out

The Dunlosky review cautions that no technique eliminates the need for student motivation, and that some strategies require guidance before students use them well — elaborative interrogation, for example, can be difficult for learners who lack background knowledge on a topic, and younger students may need coaching to apply certain techniques effectively.

• Test yourself instead of rereading notes passively.
• Spread review sessions across days or weeks rather than cramming before a deadline.
• Mix related topics or problem types instead of finishing one before starting the next.
• Explain concepts in your own words and ask yourself why and how they are true.
• Pair text with a diagram, sketch, or other visual format.
• Attach a concrete example to abstract ideas before moving on.