Study techniques that actually work, according to research

Two study techniques have the strongest evidence: practice testing, which means pulling information out of memory with quizzes, flashcards, or blank-page recall, and distributed practice, which means spreading study over several sessions instead of cramming. Rereading and highlighting, the habits most students rely on, were rated low utility in a major 2013 review. Self-explanation, elaborative interrogation, and interleaving sit in between.

The ratings: ten techniques compared

In 2013, John Dunlosky and four colleagues reviewed the research on ten popular study techniques for Psychological Science in the Public Interest. They asked whether each technique's benefits hold across four kinds of variation: learning conditions, student characteristics such as age and prior knowledge, materials, and the type of test or task. Then they rated each one.

Rating	Techniques
High utility	Practice testing, distributed practice
Moderate utility	Elaborative interrogation, self-explanation, interleaved practice
Low utility	Summarization, highlighting or underlining, the keyword mnemonic, imagery use for text learning, rereading

The two high-utility techniques earned that rating because they "benefit learners of different ages and abilities" and boost performance on many kinds of tests, including in real classrooms. The moderate ones show promise, but the evidence was limited when the review was written. For example, the benefits of interleaving "have just begun to be systematically explored."

A low rating does not mean useless in every case. It means the benefit was limited or inconsistent. The authors' advice on the two most common habits is direct: rereading and highlighting "do not consistently boost students' performance, so other techniques should be used in their place (e.g., practice testing instead of rereading)."

Retrieval practice: test yourself to learn

Practice testing is often called retrieval practice. The classic experiment is by Henry Roediger and Jeffrey Karpicke, published in Psychological Science in 2006. Students read short prose passages. Then they either reread the passage or took a recall test, writing down what they remembered, with no feedback.

The results flipped with time:

After 5 minutes, rereading won: 81% recalled versus 75%.
After 2 days, testing won: 68% versus 54%.
After 1 week, testing still won: 56% versus 42%.

In a second experiment, students who studied once and took three tests recalled 61% after a week. Students who studied four times recalled 40%, even though they had read the passage about 14 times and the tested group only about 3 times. The rereaders also felt more confident that they would remember. That gap between feeling and result is why rereading is so popular.

The finding has held up widely. A 2017 meta-analysis in the Review of Educational Research by Olusola Adesope and colleagues concluded that practice tests are more beneficial for learning than restudying and all other comparison conditions, with effects that vary by the features of the test, the learners, and the study.

Add feedback. Multiple-choice questions carry one risk: you may remember a wrong option. A 2008 study by Andrew Butler and Roediger found that feedback, given right away or later, increased correct answers and reduced those wrong-option errors on a later test. The authors' advice: "Educators should provide feedback when using multiple-choice tests."

Where the evidence is debated. In 2015, Tamara van Gog and John Sweller argued that the testing effect decreases or even disappears as learning materials get more complex. Karpicke and Aue replied in the same journal that the effect is "alive and well with complex materials." A 2018 Purdue master's thesis, supervised by Karpicke, tested the question in three experiments and found no evidence that the effect disappears with complex materials. The weight of evidence favors retrieval practice, but the size of the benefit for very complex material is still argued.

How to practice retrieval

Close the book or notes.
Write or say everything you remember about the topic, or answer practice questions.
Check your answers against the source.
Spend your next study block on what you missed.

Spacing: when you study matters

Distributed practice means spreading the same total study time across sessions. In 2006, Nicholas Cepeda and colleagues published a meta-analysis in Psychological Bulletin that covered 839 assessments in 317 experiments. They found that the best gap between study sessions grows as the time until the test grows.

A 2008 study by the same group made this concrete. More than 1,350 people learned a set of facts, reviewed them after a gap of up to 3.5 months, and took a final test up to a year later. The best gap was about 20% to 40% of the time until the test for a test one week away, and about 5% to 10% for a test one year away.

What that means in practice:

Test in	Review again after about
1 week	1 to 3 days
1 year	3 to 5 weeks

These numbers come from fact learning. Treat them as a starting point, not an exact schedule. The direction is clear: a gap of a few days beats studying the same thing twice in one evening.

Why rereading and highlighting feel effective

In a 2009 survey of 177 college students, Karpicke, Butler, and Roediger found that a majority repeatedly read their notes or textbook, and relatively few tested themselves. The authors suggest students experience "illusions of competence." Rereading makes the text feel familiar, and familiarity feels like knowing. The 2006 experiment shows the cost: the rereaders were the most confident and remembered the least a week later.

You still need to read the material once with care. The problem is spending your second and third hours rereading when you could be testing yourself.

The middle tier: worth using where they fit

Elaborative interrogation: ask yourself why a fact is true, and answer it.
Self-explanation: explain to yourself how a new idea connects to what you know, or why each step of a solution works.
Interleaved practice: mix different types of problems in one session instead of doing all of one type, then all of the next.

Dunlosky's team rated these moderate because the evidence was more limited, not because they fail. They pair well with retrieval practice.

A weekly plan built on the evidence

Day 1: Read the material once, carefully. Close it and write what you remember. Check, and note the gaps.
Day 2 or 3: Take a short quiz or recall test without notes. Check every answer, and read the explanation for each one you missed.
Day 5 to 7: Test yourself again on all of it, with problems mixed together.
Before the exam: Use the remaining time for practice tests, not rereading.
After the exam: If you need it later, review again weeks later, not days.

Where Gregator fits

Gregator is our product, and its quizzes follow the retrieval-with-feedback pattern above. Each Chapter of a course has up to five multiple-choice questions with an explanation for every option, plus a final course quiz, and a wrong answer links back to the Chapter section that covers it. Progress is tracked per Chapter and per course, so you can see what you have covered. Gregator does not schedule spaced reviews for you, so put your return visits on your calendar, using the gaps above.

Frequently asked questions

What is the most effective study technique?

Practice testing, or retrieval practice, together with spacing. Both were rated high utility in the 2013 review by Dunlosky and colleagues, because their benefits held across ages, abilities, materials, and test types.

How far apart should I space study sessions?

Longer gaps for longer goals. In one large study, the best gap was about 20% to 40% of the time until the test for a test one week away, and about 5% to 10% for a test one year away.

Is highlighting a waste of time?

Not entirely, but it was rated low utility because it does not consistently improve test performance. If you highlight, follow it with self-testing on what you marked.

Are flashcards a good study method?

Yes, when you try to recall the answer before you flip the card. That makes them a form of retrieval practice. Spread your flashcard sessions over several days.

Does cramming work?

For a test in the next few minutes or hours, it can. In the 2006 experiment, rereading won on a 5-minute test but lost on tests two days and one week later.