Learning Science Glossary
Short, sourced definitions of the terms behind effective learning and reading. Each entry links to the research and to a deeper article when we have one.
Active Recall
Active recall is a study method where you deliberately retrieve information from memory, by answering questions or reciting from a blank page, instead of rereading it. The act of retrieval strengthens the memory itself, which is why recall-based study consistently outperforms passive review in controlled experiments.
Blurting Method
The blurting method is a study technique where you read a section, close the source, and write down everything you can remember on a blank page, then check the original to find the gaps. It is a student-friendly name for free recall, one of the strongest forms of retrieval practice.
Cognitive Load
Cognitive load is the demand a task places on working memory, which can hold only a few items at once. John Sweller's cognitive load theory argues that learning fails when this limited capacity is consumed by unnecessary processing, so instruction and study should minimize distraction and build knowledge in manageable steps.
Commonplace Book
A commonplace book is a personal notebook where a reader collects quotations, ideas, and observations from their reading, usually organized by theme rather than by date. Kept since antiquity and especially popular during the Renaissance, it is the ancestor of the modern highlight library and second brain.
Desirable Difficulties
Desirable difficulties are learning conditions that make practice feel harder and slower in the moment but produce stronger long-term retention and transfer. The term was coined by Robert Bjork. Spacing sessions apart, mixing topics, and testing yourself are all desirable difficulties; easy, fluent study often is not durable study.
Dual Coding
Dual coding is Allan Paivio's theory that the mind processes information through two connected systems, one verbal and one visual, and that material encoded in both forms is remembered better than material encoded in one. Combining words with relevant images gives memory two routes back to the same idea.
Elaborative Interrogation
Elaborative interrogation is a study technique where you generate explanations for stated facts by repeatedly asking why: why is this true, why does it make sense? Producing the explanation yourself connects new information to what you already know, which improves memory compared with simply reading the fact.
Feynman Technique
The Feynman technique is a learning method where you explain a concept in plain language, as if teaching it to a child, to expose exactly where your understanding breaks down. You then return to the source to repair those gaps and simplify again. It is named after physicist Richard Feynman.
Forgetting Curve
The forgetting curve describes how memory for new material declines over time: loss is steepest in the first hours and days, then levels off. Hermann Ebbinghaus first measured it in the 1880s, and a 2015 replication confirmed the shape. Spaced review is the standard countermeasure, resetting the curve at each visit.
Generation Effect
The generation effect is the finding that information you produce yourself is remembered better than information you merely read. First delineated by Slamecka and Graf in 1978, it has been confirmed by meta-analysis across dozens of studies, with self-generated material enjoying an average advantage of roughly half a standard deviation.
Highlighting
Highlighting is marking selected text while reading to flag what matters. Used alone, it is weak: the landmark Dunlosky review rated mark-and-reread low utility for learning. Used selectively as a capture step that feeds recall, notes, and spaced review, it becomes the front door to techniques that do work.
Incremental Reading
Incremental reading is a method of reading many texts in parallel, in small prioritized portions, while extracting key passages into a spaced repetition system for long-term retention. Conceived by SuperMemo creator Piotr Wozniak around 1999, it merges reading, highlighting, and review scheduling into one continuous process.
Interleaving
Interleaving is a practice schedule that mixes different topics or problem types within a session instead of finishing one before starting the next. Mixing forces you to discriminate between problem types and choose the right approach, which hurts practice performance but improves later test performance, especially in math and category learning.
Marginalia
Marginalia are the notes, marks, and commentary a reader writes in the margins of a text. More than decoration, they are a record of a mind responding to an author in real time. H. J. Jackson's history of the practice traces three centuries of readers writing back to their books.
Metacognition
Metacognition is thinking about your own thinking: knowing what you know, monitoring your comprehension as you learn, and regulating your strategies accordingly. The concept was formalized by John Flavell in 1979. Accurate metacognition is what separates learners who study what they need from learners who reread what feels familiar.
Mind Mapping
Mind mapping is a note-taking method that arranges ideas as a radial diagram: a central topic branches into subtopics, keywords, and images instead of linear sentences. Popularized by Tony Buzan, it externalizes the structure of a subject, and controlled research shows a recall benefit for written material.
Personal Knowledge Management
Personal knowledge management, or PKM, is the individual practice of capturing, organizing, connecting, and reusing the information you encounter, so that reading and experience accumulate into usable knowledge instead of evaporating. It spans tools like note apps and highlighters and methods like Zettelkasten, second brains, and Harold Jarche's seek, sense, share loop.
Progressive Summarization
Progressive summarization is Tiago Forte's technique for distilling notes in layers over time: save the passage, bold the best parts on a later visit, highlight the best of the bold on another, and eventually summarize in your own words. Each pass compresses the note only as much as its usefulness has earned.
Protege Effect
The protege effect is the finding that people learn material better when they learn it in order to teach someone else. Teaching, or even preparing to teach, increases effort, organization, and reflection. The term comes from research on teachable software agents, where students worked harder for their virtual pupils than for themselves.
Retrieval Practice
Retrieval practice is the strategy of bringing information to mind from memory, through self-testing, free recall, or answering questions, as a way of learning it more deeply. It is the mechanism behind active recall and the testing effect, and it outperforms rereading and many elaborate study methods in experiments.
Second Brain
A second brain is a trusted digital system, typically a notes app fed by highlights and captures, that stores your ideas, references, and insights outside your head so they can be searched, connected, and reused. The term was popularized by Tiago Forte's methodology and 2022 book Building a Second Brain.
Spaced Repetition
Spaced repetition is a review schedule that spreads practice sessions out over increasing intervals of time instead of massing them together. Reviewing material just as it starts to fade produces far more durable memory than cramming, a finding replicated across more than a century of experiments on distributed practice.
Spacing Effect
The spacing effect is the finding that learning distributed across multiple sessions produces better long-term retention than the same amount of learning massed into one session. First measured by Ebbinghaus in the 1880s, it is among the oldest and most robust results in memory research.
Testing Effect
The testing effect is the finding that taking a test on material improves long-term retention more than spending the same time restudying it. Tests are not just measurement; the act of retrieval itself strengthens memory. It is one of the most replicated results in learning research.
Transfer of Learning
Transfer of learning is the application of knowledge or skills learned in one context to a different context, from a nearby problem to a distant domain. It is the real goal of most education, yet far transfer is hard to achieve, and Barnett and Ceci's taxonomy explains why claims about it so often conflict.
Zettelkasten
A Zettelkasten, German for slip box, is a note-taking system of small, atomic notes written in your own words and densely linked to one another. Sociologist Niklas Luhmann credited his slip box of tens of thousands of interlinked notes as a partner in producing his enormous body of scholarly work.