How to Study for Exams: 5 Science-Backed Methods That Actually Work

You have an exam coming up. You're staring at a stack of notes, a highlighted textbook, and a vague plan to "review everything." Here's the problem: rereading notes is one of the least effective study methods ever measured.

Dunlosky et al. (2013) reviewed 10 common study techniques and rated rereading and highlighting as "low utility." The two techniques rated "high utility"? Practice testing and distributed practice. Most students spend 80% of their time on the methods that work least.

Here are the five techniques that actually move exam scores—ranked by research evidence— with a concrete day-by-day plan.

The 5 Techniques, Ranked by Research Evidence

Study Techniques Ranked by Effectiveness (Dunlosky et al., 2013)

Technique	Utility Rating	Effect on Retention
1. Practice testing (active recall)	High	80% retention at 7 days vs 36% for rereading
2. Distributed practice (spaced repetition)	High	10-30% better than cramming
3. Interleaved practice	Moderate	43% better on delayed tests vs blocked study
4. Elaborative interrogation	Moderate	Asking "why?" deepens encoding
5. Self-explanation	Moderate	Explaining material to yourself strengthens memory traces

Notice what's not on this list: rereading, highlighting, summarizing, and keyword mnemonics. All were rated "low utility." Yet these are what most students default to under pressure.

1. Practice Testing (Active Recall)

Active recall means testing yourself on material instead of passively reviewing it. Close your notes. Ask yourself: "What were the three causes of X?" Try to produce the answer from memory. Then check.

The research is staggering. Karpicke & Roediger (2008) published in Science that students who practiced retrieval retained 80% of material after one week, while students who re-studied retained only 36%. That's a 2.2x difference from simply changing how you review.

Roediger & Butler (2011) found that testing doesn't just measure knowledge—it changes it. Every time you successfully retrieve information, the memory trace gets stronger and more connected to related concepts. Failed retrieval attempts are valuable too: they create a "desirable difficulty" that enhances subsequent learning.

How to Apply It

• Flashcards — the classic approach. Create cards with questions on the front and answers on the back. Tools like Anki add spaced repetition scheduling
• The blank page method — close your notes, grab a blank sheet, write everything you remember about a topic. Compare with your notes. The gaps are what you need to study
• Practice problems — for quantitative subjects, solving new problems from scratch (not reworking examples) is active recall in action
• AI-generated quizzes — tools like LearnLog generate quiz questions from what you've learned, removing the card-creation step entirely

2. Distributed Practice (Spaced Repetition)

Spaced repetition means spreading your study sessions across days and weeks instead of cramming everything into one marathon session. It's the second technique rated "high utility" by Dunlosky et al.

Cepeda et al. (2006) analyzed 184 articles and found that spaced practice produces 10-30% better retention than massed practice (cramming). The key insight: your brain consolidates memories between study sessions. Sleep plays a critical role— Diekelmann & Born (2010) showed that memory consolidation happens during sleep, which is why spacing study across days outperforms spacing within a single day.

The Optimal Spacing Schedule

Cepeda et al. (2008) found the optimal gap between study sessions depends on when you need to remember the material:

Optimal Study Spacing Based on Exam Timeline

Exam in...	Optimal gap between sessions	Number of sessions
1 week	1-2 days	3-4 sessions
1 month	3-5 days	5-7 sessions
3 months	1-2 weeks	6-10 sessions
1 year	3-4 weeks	12+ sessions

The practical takeaway: start studying earlier and do shorter, more frequent sessions. Three 30-minute sessions spaced across a week beat one 3-hour cramming marathon the night before—even though the total time is less.

3. Interleaved Practice

Interleaving means mixing different topics or problem types within a single study session instead of finishing one topic before moving to the next (called "blocking").

Rohrer & Taylor (2007) tested math students and found that interleaved practice led to 43% better scores on a delayed test compared to blocked practice—even though students in the blocked group felt more confident during study.

Why does mixing topics help? It forces your brain to practice discriminating between problem types and selecting the right strategy—skills that exams directly test. Blocked study lets you run on autopilot; interleaving makes you think.

How to Apply It

• Mix problem types — instead of doing 20 calculus integration problems in a row, mix integration, differentiation, and limits
• Alternate subjects — study biology for 25 minutes, switch to history for 25 minutes, then back to biology
• Shuffle flashcards — don't study one deck at a time. Mix cards from different subjects in a single session

4. Elaborative Interrogation

This one is simple: ask "why?" and "how?" after every fact you study.

Instead of just memorizing "The mitochondria is the powerhouse of the cell," ask: "Why is it called the powerhouse? How does it generate energy? What happens when mitochondria malfunction?"

Pressley et al. (1987) showed that asking "why" questions during study significantly improves factual recall because it creates richer memory traces connected to existing knowledge. You're not just storing a fact—you're building a web of understanding around it.

5. Self-Explanation

Self-explanation means pausing while studying to explain the material to yourself in your own words—out loud or in writing. It's the technique behind the Feynman Technique: if you can't explain it simply, you don't understand it.

Chi et al. (1989) found that students who explained material to themselves as they studied performed significantly better on subsequent tests than students who simply read the same material. The act of generating explanations forces you to identify gaps in your understanding that passive reading hides.

How to Apply It

• Teach an imaginary student — explain the concept as if someone asked you "What does that mean?"
• Write a one-paragraph summary — close your notes, write the explanation, then check for errors
• Voice-note it — record yourself explaining a concept in 30-60 seconds. Play it back and spot the gaps

Your Day-by-Day Exam Study Plan

Here's a concrete plan that combines all five techniques. Adjust the timeline based on when your exam is.

14 Days Before the Exam

What to Stop Doing Immediately

These popular study methods are rated "low utility" by Dunlosky et al. (2013). They feel productive but produce weak memories:

• Rereading notes or textbooks — creates a "fluency illusion." Recognizing information feels like knowing it, but recognition and recall are different memory processes. Exams test recall.
• Highlighting — requires no cognitive effort. You're selecting text, not processing it. Dunlosky's team found no measurable benefit over simply reading.
• Summarizing — slightly better than rereading, but still passive. If you summarize, test yourself on the summary afterward. The summary alone isn't enough.
• All-night cramming — Diekelmann & Born (2010) showed memory consolidation happens during sleep. Pulling an all-nighter sabotages the biological process that turns short-term memories into long-term ones.

The Science of Sleep and Exam Performance

This isn't a soft recommendation—sleep is a study technique.

Walker & Stickgold (2006) demonstrated that a full night of sleep after learning produces 20-40% better recall the next day compared to the same duration awake. During slow-wave sleep, your hippocampus replays the day's learning and transfers it to long-term cortical storage.

The implication is direct: studying for 3 hours then sleeping 8 hours produces better exam performance than studying for 8 hours and sleeping 3 hours. Your brain needs downtime to consolidate what you learned.

The Research

• Dunlosky et al. (2013) reviewed 10 study techniques across hundreds of studies, rating practice testing and distributed practice as "high utility" and rereading/highlighting as "low utility," published in Psychological Science in the Public Interest
• Karpicke & Roediger (2008) demonstrated in Science that retrieval practice produces 80% retention at 7 days vs 36% for repeated studying
• Cepeda et al. (2006) found spaced practice produces 10-30% better retention than massed practice across a meta-analysis of 184 articles
• Rohrer & Taylor (2007) showed interleaved practice leads to 43% better scores on delayed tests compared to blocked practice
• Diekelmann & Born (2010) established sleep as a critical factor in memory consolidation, published in Nature Reviews Neuroscience
• Chi et al. (1989) demonstrated that self-explanation during study significantly improves subsequent test performance

Key Takeaways

• Active recall produces 80% retention at 7 days vs 36% for rereading—the single most impactful change you can make
• Spaced repetition improves retention by 10-30% over cramming—start studying earlier, not harder
• Interleaving (mixing topics) boosts delayed test scores by 43% compared to studying one topic at a time
• Sleep is a study technique: 20-40% better recall after a full night's sleep vs staying awake
• Rereading and highlighting are rated "low utility"—stop spending time on them

Continue Learning

• Active Recall: The #1 Study Technique
• How Spaced Repetition Works
• The Forgetting Curve Explained
• The Pomodoro Technique for Study Sessions
• The Feynman Technique
• Cornell Notes for Better Retention