Introduction
Most students rely heavily on study techniques like highlighting, re-reading notes, and cramming before exams, largely because these methods feel productive and are what generations of students have simply always done. Yet decades of cognitive science research consistently show these popular techniques are among the least effective methods for actual long-term learning.
A major 2013 review published in Psychological Science in the Public Interest, evaluating dozens of study techniques against rigorous experimental evidence, found that a small handful of methods reliably outperform the rest — and they are rarely the ones students actually use most.
Retrieval Practice: Testing Yourself Works Better Than Re-Reading
The single most well-supported technique across cognitive science research is retrieval practice — actively trying to recall information from memory, such as through practice tests or flashcards, rather than simply re-reading source material. The effort of retrieving information, even when you get it wrong and have to check the answer, appears to strengthen memory far more than passive review.
This effect, sometimes called the 'testing effect,' has been replicated across many studies and subject areas: students who use practice testing consistently outperform students who spend the same amount of time re-reading, even when both groups report re-reading feels more effective while studying.
Spaced Repetition Beats Cramming
Spaced repetition, or distributed practice, involves spreading study sessions out over time with increasing intervals, rather than massing all studying into one or two long sessions right before a test, commonly known as cramming. Research consistently shows that spaced practice produces significantly better long-term retention than the same total amount of study time crammed into fewer sessions.
While cramming can produce reasonable short-term recall for an exam the next day, information studied this way tends to be forgotten far faster afterward, whereas spaced practice, though it feels harder and less fluent in the moment, produces memory that lasts weeks, months, or years longer.
Interleaving: Mixing Topics Instead of Blocking Them
Most students study one topic thoroughly before moving to the next, a method called 'blocked practice.' Research on a technique called interleaving — mixing different but related topics or problem types within a single study session, rather than mastering one before starting another — has found it produces better long-term learning and improved ability to correctly identify which method or concept applies to a new problem.
Interleaving is particularly well-studied in mathematics education, where students who practice mixed problem sets, rather than blocks of identical problem types, show significantly better performance on later tests that require identifying the correct approach rather than simply repeating a memorized procedure.
Why Ineffective Methods Remain So Popular
Highlighting and re-reading persist as dominant study strategies largely because of a phenomenon researchers call the 'illusion of fluency': as students re-read familiar material, the text starts to feel easy and recognizable, which is mistakenly interpreted as evidence of true understanding, even though recognition and genuine retrieval ability are very different cognitive skills.
Effective techniques like retrieval practice and spaced repetition, by contrast, often feel harder and more frustrating in the moment, precisely because they require genuine effortful recall rather than passive recognition — which is exactly the 'desirable difficulty' that cognitive scientists have found actually drives durable learning.
Sources
- Psychological Science in the Public Interest — Major peer-reviewed review of study technique effectiveness
- American Psychological Association — Cognitive science research on learning and memory
- Retrieval Practice Research Group — Academic research summaries on retrieval practice and spaced repetition
FAQ
What is retrieval practice and why does it work?
Retrieval practice means actively trying to recall information from memory, such as through practice tests, rather than re-reading source material. The effort of retrieving information appears to strengthen memory far more than passive review.
Is cramming ever effective for studying?
Cramming can produce reasonable short-term recall for a test the next day, but information studied this way is forgotten far faster afterward compared to spaced repetition, which produces longer-lasting memory.
What is interleaving in studying?
Interleaving means mixing different but related topics or problem types within a single study session, rather than mastering one topic fully before moving to the next, which research shows improves long-term learning.
Why do students keep using highlighting and re-reading if they don't work well?
These methods create an 'illusion of fluency' where familiar text feels easy and recognizable, which students mistakenly interpret as true understanding, even though recognition differs from genuine retrieval ability.
What did the major 2013 review find about study techniques?
A widely cited 2013 review in Psychological Science in the Public Interest evaluated dozens of study techniques and found retrieval practice and spaced repetition to be among the most effective, while highlighting and re-reading rated poorly.
About the Author
doyouknow.app Editorial Team — We reference peer-reviewed cognitive science research to identify study techniques with genuine, replicated evidence behind them.
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