Get a definitive ranking of popular study techniques based on scientific evidence. Learn which methods deserve your time and which to avoid.
In 2013, cognitive psychologist John Dunlosky and his colleagues published a landmark paper in Psychological Science in the Public Interest. They analyzed decades of research on learning techniques and rated each one's effectiveness. The findings shattered conventional wisdom—highlighting, the most popular study method among students, ranked near the bottom.
This ranking draws directly from that meta-analysis, updated with subsequent research. Each technique receives its original utility rating along with the evidence behind it.
The Dunlosky Rankings at a Glance
| Rank | Technique | Utility Rating | Research Confidence |
|---|---|---|---|
| 1 | Practice Testing | High | Very Strong |
| 2 | Distributed Practice | High | Very Strong |
| 3 | Elaborative Interrogation | Moderate | Strong |
| 4 | Self-Explanation | Moderate | Strong |
| 5 | Interleaved Practice | Moderate | Growing |
| 6 | Summarization | Low | Moderate |
| 7 | Highlighting/Underlining | Low | Strong (negative) |
| 8 | Keyword Mnemonic | Low | Mixed |
| 9 | Imagery for Text | Low | Limited |
| 10 | Rereading | Low | Strong (negative) |
The Shocking Truth About Popular Methods
Highlighting, rereading, and summarization—techniques used by 80%+ of students—all received LOW utility ratings. Most study time is spent on ineffective methods.
Tier One: High-Utility Techniques
Practice Testing (Retrieval Practice)
Utility Rating: HIGH
Practice testing means actively recalling information from memory rather than passively reviewing it. This includes flashcards, practice exams, free recall exercises, and self-quizzing.
The research behind this is overwhelming. Roediger and Karpicke (2006) demonstrated that students who practiced retrieval retained 80% of material after one week, compared to 36% for those who reread passages four times. The effect holds across age groups, subjects, and testing formats.
What makes retrieval powerful is the "testing effect"—the act of pulling information from memory fundamentally changes how that memory is stored. Each successful retrieval strengthens neural pathways and creates new retrieval routes.
Practical application: After reading a chapter, close the book and write everything you remember. Use flashcard apps like Anki. Take practice tests under exam conditions. The struggle of retrieval is where learning happens.
Surprising Benefit
Failed retrieval attempts are nearly as valuable as successful ones. The effort of trying to remember—even when you can't—primes the brain to encode information more deeply on the next exposure.
Distributed Practice (Spacing Effect)
Utility Rating: HIGH
Distributed practice involves spreading study sessions across time rather than massing them together. Instead of studying for six hours before an exam, study for one hour across six different days.
Cepeda et al. (2006) analyzed 317 spacing studies and found a consistent pattern: optimal retention occurs when the gap between study sessions equals 10-20% of the desired retention interval. For a test in one month, space sessions 3-6 days apart.
The spacing effect was first documented by Hermann Ebbinghaus in 1885, making it one of the oldest findings in cognitive psychology. Yet most students still cram.
Why cramming fails: Massed practice creates an illusion of competence. Information feels familiar during the cramming session but evaporates within days. Spaced practice feels harder in the moment but produces retention that lasts months or years.
Practical application: Use a calendar to schedule review sessions. Study new material, then revisit after 1 day, 3 days, 1 week, and 2 weeks. Tools like Anki automate this with spaced repetition algorithms.
Tier Two: Moderate-Utility Techniques
Elaborative Interrogation
Utility Rating: MODERATE
Elaborative interrogation involves generating explanations for facts by asking "why" and "how" questions. Rather than simply memorizing that "the heart pumps blood," you ask: "Why does blood need to circulate? How does the pumping mechanism work?"
Dunlosky's analysis found this technique consistently outperformed rereading, with effect sizes around d = 0.87 in multiple studies. However, it requires sufficient prior knowledge to generate meaningful explanations.
Limitation: This technique works best when learners already have foundational knowledge in a domain. Complete beginners may struggle to generate accurate explanations and could even reinforce misconceptions.
Practical application: For each key fact, write down a "why" explanation in your own words. Then check your reasoning against the source material. The goal is generating connections, not perfect accuracy on the first try.
Self-Explanation
Utility Rating: MODERATE
Self-explanation involves pausing during learning to explain to yourself what new information means and how it relates to prior knowledge. Chi et al. (1989) found that students who self-explained during problem-solving performed dramatically better on transfer problems.
Unlike elaborative interrogation (which asks "why"), self-explanation focuses on "what does this mean" and "how does this connect." It's particularly effective for procedural knowledge and complex problem-solving.
The integration advantage: Self-explanation forces you to notice gaps in your understanding. Students who simply read through material often don't realize what they missed until the exam.
Practical application: After each paragraph or problem step, verbalize what you just learned. Explain it as if teaching someone else. If you can't explain it clearly, you've identified a gap that needs attention.
Interleaved Practice
Utility Rating: MODERATE
Interleaved practice means mixing different problem types or topics within a single study session, rather than completing all problems of one type before moving to the next.
Rohrer and Taylor (2007) had students practice geometry problems. Those who interleaved scored 43% higher on a delayed test compared to those who blocked practice by problem type.
The discrimination hypothesis: Interleaving forces your brain to constantly identify which strategy applies to each problem. Blocked practice lets you apply the same procedure mindlessly, which feels easier but doesn't build transferable skills.
Why It Feels Wrong
Interleaving feels more difficult and produces worse performance during practice. But this 'desirable difficulty' is precisely what drives long-term learning. Don't trust how it feels—trust the research.
Practical application: When doing practice problems, shuffle different types together. When studying multiple chapters, rotate between them in a single session rather than finishing one before starting another.
Tier Three: The Methods That Fail Students
Summarization
Utility Rating: LOW
Summarization can be effective, but only when done skillfully. The problem: most students create summaries that are either too detailed (copying) or miss key concepts entirely. Training in summarization techniques can help, but few students receive this training.
When it works: Summarization benefits learners who already understand the material well enough to identify main ideas. It's more useful as a check on understanding than as a primary learning technique.
Highlighting and Underlining
Utility Rating: LOW
Perhaps the most popular study technique is also one of the least effective. Multiple studies show highlighting provides no benefit beyond simply reading—and may actually harm learning by creating an illusion of understanding.
The fundamental problem: highlighting is passive. Running a marker over text requires no processing, no retrieval, no connection-building. Highlighted text looks important without actually becoming important in memory.
The illusion trap: Brightly colored text feels salient when reviewing notes. But recognition ("I remember highlighting this") differs entirely from recall ("I can reproduce this information from memory"). Students mistake the former for the latter.
Rereading
Utility Rating: LOW
Rereading is the default study strategy for most students: read the chapter, read it again before the test. Callender and McDaniel (2009) found that two readings produced minimal benefit over one reading—and dramatically underperformed practice testing.
Rereading creates fluency without comprehension. Text that initially felt challenging becomes easy on the second pass, which students interpret as learning. But this fluency reflects familiarity, not transferable knowledge.
Building Your Evidence-Based Study System
| Study Phase | Primary Technique | Supporting Technique | Time Allocation |
|---|---|---|---|
| Initial Learning | Self-Explanation | Elaborative Interrogation | 30% |
| Consolidation | Practice Testing | Interleaved Practice | 50% |
| Long-term Retention | Distributed Practice | Practice Testing | 20% |
The Comfort Trap
Effective techniques feel harder than ineffective ones. Rereading feels smooth; retrieval feels effortful. Blocked practice feels productive; interleaving feels frustrating. Use difficulty as a signal you're learning.
The Research Continues
Since Dunlosky's 2013 paper, additional research has refined these findings. Key updates:
Retrieval practice benefits transfer: Earlier concerns that testing only helped with tested material have been addressed. Recent studies show retrieval practice improves ability to apply knowledge to new problems.
Interleaving works beyond motor skills: Initial interleaving research focused on physical skills. Studies now confirm benefits for conceptual learning, foreign language acquisition, and medical diagnosis.
Spacing and testing combine powerfully: Using both techniques together produces effects larger than either alone. The combination appears to be especially robust for long-term retention.
From Research to Reality
The gap between learning science and common practice remains vast. Students continue highlighting, rereading, and cramming because these methods feel easier and nobody taught them alternatives.
The techniques in Tier One and Tier Two require more effort. They feel less fluent in the moment. They demand active engagement rather than passive consumption. This is precisely why they work.
Dunlosky's meta-analysis wasn't about finding shortcuts. It was about identifying where effort actually pays off—and where effort is wasted on strategies that look like studying but don't produce learning.
The Bottom Line
Two techniques—practice testing and distributed practice—received the highest utility rating across all evidence reviewed. Everything else is secondary.
If you change nothing else about how you study, replace rereading with self-testing and replace cramming with spacing. The research is clear.