Picture two students studying the same textbook chapter. The first student reads through each page carefully, highlighting key sentences and moving steadily forward. The second student reads more slowly, frequently pausing to explain to herself what she just read, why it makes sense, and how it connects to what she already knows. Both students spend the same amount of time studying. But when the test comes, the second student dramatically outperforms the first. The difference is not talent or intelligence. It is a technique called self-explanation, and it is one of the most effective learning strategies ever studied.
What Is the Self-Explanation Effect?
The self-explanation effect refers to the well-documented finding that learners who explain material to themselves, generating explanations for why concepts are true, how steps in a procedure follow from each other, or how new information relates to what they already know, learn more deeply and retain more information than learners who simply read or study the same material without generating explanations.
Self-explanation is distinct from simply re-reading or even summarizing. When you summarize, you condense information into shorter form. When you self-explain, you elaborate on the information by making inferences, identifying principles, connecting new information to prior knowledge, and reasoning through the logic behind facts and procedures. It is an active, constructive process that goes beyond the information given on the page.
The technique does not require explaining to another person, though that can also be beneficial. The key is the act of generating explanations, even if the only audience is yourself. You can self-explain silently in your head, whisper to yourself, or write your explanations down. The format matters less than the process of actively constructing meaning.
The Research Behind Self-Explanation
Michelene Chi's Foundational Work
The self-explanation effect was first identified and extensively studied by Michelene Chi and her colleagues at the University of Pittsburgh in the late 1980s and early 1990s. In her landmark 1989 study, Chi examined how students learned from worked examples in physics. She found dramatic differences between successful and unsuccessful learners that had nothing to do with how much time they spent studying.
Successful learners spontaneously engaged in self-explanation while studying worked examples. They would pause after each step and ask themselves questions like "Why does this step follow from the previous one?" and "What principle justifies this operation?" They generated inferences that went beyond the information explicitly stated in the examples. Unsuccessful learners, by contrast, read through the examples passively, perhaps re-reading steps multiple times but never generating their own explanations.
Chi found that the high self-explainers solved novel problems correctly about 82 percent of the time, while low self-explainers solved them correctly only about 46 percent of the time. This was not a small difference. The self-explanation effect was large enough to distinguish between students who appeared to understand the material and students who clearly did not.
Extension to Other Domains
Subsequent research has demonstrated that the self-explanation effect is remarkably robust across different subjects, age groups, and learning contexts.
Renkl (1997) confirmed Chi's findings in mathematics learning and further demonstrated that the quality of self-explanations matters. Students who generated principle-based explanations, explanations referencing underlying rules or concepts, learned more than students who generated superficial or paraphrasing explanations.
McNamara (2004) showed that self-explanation training improved reading comprehension for college students, particularly for students with low prior knowledge who were reading difficult texts. The training helped students develop the habit of making inferences, connecting ideas across sentences, and relating text information to their background knowledge.
Wylie and Chi (2014) conducted a comprehensive review of self-explanation research and concluded that self-explanation is effective across a wide range of domains including science, mathematics, reading comprehension, and procedural learning. They also found that prompting students to self-explain, even when they would not do so spontaneously, produces significant learning benefits.
Comparison with Other Strategies
In the influential review by Dunlosky and colleagues (2013), self-explanation was rated as having moderate utility for learning. It was ranked higher than popular strategies like highlighting, re-reading, and keyword mnemonics, and was noted for its broad applicability across different types of learning materials and student populations.
Research comparing self-explanation to other active learning strategies has shown that it is particularly effective for developing deep understanding and transfer, the ability to apply learned concepts to new problems and situations. While some other strategies may be more efficient for rote memorization, self-explanation excels at building the kind of flexible, principled understanding that supports real-world application.
Why Self-Explanation Works
Several cognitive mechanisms explain the effectiveness of self-explanation.
Generating Inferences
Self-explanation forces you to generate inferences that go beyond the information explicitly presented. When you explain why a step in a procedure works or how a new fact relates to a principle, you are constructing new knowledge that fills gaps in the presented material. These inferences create a more complete and coherent mental representation of the material.
Most learning materials have implicit gaps, places where the author assumes background knowledge or skips intermediate reasoning steps. Passive readers often glide over these gaps without noticing them. Self-explainers are forced to confront and fill these gaps, which produces deeper understanding.
Integrating New and Prior Knowledge
Self-explanation prompts you to connect new information to what you already know. When you explain to yourself why a new fact makes sense, you inevitably draw on your existing knowledge, creating links between new and old information. These connections embed the new information within your existing knowledge network, making it more meaningful and more memorable.
Identifying and Repairing Misunderstandings
When you attempt to explain something and find that your explanation does not make sense or is incomplete, you have identified a misunderstanding or knowledge gap. This detection is critical because it allows you to take corrective action, such as re-reading the relevant material, seeking additional resources, or revising your mental model. Without self-explanation, misunderstandings can persist undetected.
Promoting Active Processing
Self-explanation transforms reading from a passive process into an active, constructive one. Instead of simply absorbing information, you are actively building and organizing knowledge structures. Research on the active learning framework by Chi (2009) distinguishes between passive, active, constructive, and interactive learning activities, with constructive activities like self-explanation consistently producing better outcomes than passive or merely active ones.
Building Mental Models
Through self-explanation, you construct mental models, integrated representations of how systems, processes, or concepts work. These mental models allow you to reason about the material, make predictions, and solve novel problems. A student who can explain why a particular chemical reaction occurs has a mental model of the underlying chemistry that supports flexible problem solving, while a student who has merely memorized the reaction equation has a brittle representation that may fail when the problem changes.
How to Practice Self-Explanation
While Reading Textbooks
Pause after each paragraph, section, or key concept and ask yourself these questions:
- "What did I just read, in my own words?" This ensures you are processing the meaning rather than just moving your eyes across the page.
- "Why does this make sense?" This forces you to connect the new information to underlying principles or prior knowledge.
- "How does this relate to what I read earlier?" This builds connections between different parts of the material.
- "What is an example of this?" This grounds abstract concepts in concrete instances.
Do not rush through these questions. Take time to formulate genuine explanations, even if it means you cover fewer pages per study session. The depth of your learning will more than compensate for the reduced pace.
While Studying Worked Examples
When studying solved problems in mathematics, physics, or other quantitative subjects, do not just read through the solution. For each step, ask yourself:
- "Why was this step taken?" Identify the principle or rule that justifies the step.
- "How does this step follow from the previous one?" Trace the logical chain of reasoning.
- "What would happen if this step were different?" Consider alternatives to deepen your understanding of why this particular approach works.
- "Could I apply this same principle to a different problem?" Begin thinking about transfer immediately.
While Watching Lectures or Videos
Pause the video periodically, ideally every few minutes, and self-explain what was just covered. You might say to yourself, "The professor just explained that supply curves shift rightward when production costs decrease. This makes sense because lower costs mean producers can supply more at every price level, so the whole curve moves to the right." This active engagement with lecture content produces far better learning than passive viewing.
While Reviewing Notes
Instead of simply re-reading your notes, use them as prompts for self-explanation. Cover a section of your notes, try to explain the concept from memory, and then check your notes to see what you missed or got wrong. This combines self-explanation with retrieval practice for a particularly powerful study approach.
While Learning Procedures
When learning step-by-step procedures, whether in science, cooking, programming, or any other domain, explain to yourself why each step is necessary and what would go wrong if it were skipped or done differently. Understanding the rationale behind each step transforms rote procedural knowledge into principled understanding.
Self-Explanation Prompts and Templates
If you are new to self-explanation, using structured prompts can help you develop the habit. Here are templates you can use until self-explanation becomes automatic.
For facts and concepts: "This is true because..." followed by your explanation of the underlying reason or mechanism.
For procedures and processes: "This step works because..." followed by your explanation of the principle or logic behind the step.
For relationships between ideas: "This connects to [other concept] because..." followed by your explanation of how the two ideas relate.
For new information: "This is similar to [familiar concept] because... but different because..." followed by your comparison and contrast.
For surprising or counterintuitive information: "This is surprising because I expected... but it makes sense because..." followed by your revised understanding.
Common Mistakes in Self-Explanation
Paraphrasing Instead of Explaining
Simply restating information in slightly different words is paraphrasing, not self-explanation. If you read "mitochondria produce ATP" and say to yourself "ATP is produced by mitochondria," you have not self-explained. A genuine self-explanation would address why or how: "Mitochondria produce ATP through the process of oxidative phosphorylation, where the energy from breaking down glucose is used to drive the synthesis of ATP from ADP and phosphate. This happens in the mitochondria because that is where the electron transport chain and the necessary enzymes are located."
Skipping Difficult Material
The material that is hardest to explain is often the material that benefits most from self-explanation. Resist the temptation to skip over confusing passages. Instead, embrace the difficulty as an opportunity to identify and address gaps in your understanding.
Being Too Brief
Effective self-explanations are typically detailed and specific. A one-word or one-sentence explanation is usually too shallow to produce significant learning benefits. Aim for explanations that address the underlying mechanisms, principles, or reasoning in sufficient detail that someone unfamiliar with the topic could understand your explanation.
Not Checking Accuracy
After generating a self-explanation, verify its accuracy against reliable sources. The learning benefit of self-explanation is greatest when your explanations are correct. If you generate an incorrect explanation and do not catch the error, you may reinforce a misunderstanding.
Combining Self-Explanation with Other Strategies
Self-explanation pairs powerfully with other evidence-based learning strategies.
Combined with retrieval practice, self-explanation becomes even more effective. First retrieve a concept from memory, then explain why it is true or how it works. This double challenge of both recalling and explaining strengthens memory and understanding simultaneously.
Combined with spaced repetition, self-explanation helps ensure that each review session involves deep processing rather than superficial re-exposure. When you revisit a concept after a delay, self-explaining it forces you to reconstruct your understanding rather than simply recognizing it.
Combined with interleaving, self-explanation helps you articulate the differences between similar concepts. When you encounter a concept from a different category than the previous one, explaining why this concept is different builds the discriminative knowledge that interleaving is designed to develop.
Conclusion
Self-explanation is a simple yet profoundly effective learning strategy. By developing the habit of explaining concepts to yourself, generating inferences, connecting new information to prior knowledge, and reasoning through the logic behind procedures, you transform passive studying into active knowledge construction. The research evidence from Chi, Renkl, McNamara, and many others consistently demonstrates that self-explanation produces deeper understanding, better retention, and greater ability to transfer knowledge to new situations. The next time you study, slow down, pause frequently, and explain to yourself what you are learning and why it makes sense. The investment of time and effort will pay dividends in the quality and durability of your learning.