How to Learn Something New Effectively

The best-supported way to learn something new is to test yourself on it and to spread your study over several sessions. Rereading and highlighting, the most common habits, help much less. A 2013 review in Psychological Science in the Public Interest looked at 10 popular study techniques. It rated only two of them high utility: practice testing and distributed practice (spacing). Those two helped learners of different ages and abilities and worked in real classrooms. Rereading and highlighting were rated low, because they don’t consistently improve performance (Dunlosky et al., 2013).

How the main techniques rate

Here is how the 2013 review rated each technique (Dunlosky et al., 2013). The definitions come from the lead author’s summary for teachers (Dunlosky, 2013).

Technique	What it means	Rating
Practice testing	Quizzing yourself on what you’re learning	High
Distributed practice	Spreading study sessions out over time	High
Elaborative interrogation	Explaining why a fact or idea is true	Moderate
Self-explanation	Explaining how new information relates to what you know	Moderate
Interleaved practice	Mixing different kinds of problems in one session	Moderate
Summarization, keyword mnemonic, imagery for text	Writing summaries, memory-cue words, picturing text	Low
Rereading	Reading the material again	Low
Highlighting	Marking important parts while reading	Low

Moderate meant promising but limited evidence. The review said elaborative interrogation and self-explanation hadn’t been tested enough in real classrooms, and research on interleaving was just getting started (Dunlosky et al., 2013).

Retrieval practice: test yourself

Pulling information out of memory strengthens it. In a classic experiment, students either reread a passage or tried to recall it. On a test five minutes later, the rereaders did better. On tests two days and one week later, the students who had practiced recall remembered substantially more. Rereading also made students more confident, even though it didn’t help them remember longer (Roediger & Karpicke, 2006).

The effect holds outside the lab. A 2021 review pooled 222 classroom studies with 48,478 students and found that quizzing raised achievement by a medium amount, with feedback among the factors that changed the size of the benefit (Yang et al., 2021). Recall tests produced bigger benefits than recognition tests such as multiple choice (Rowland, 2014). It helps with understanding too. Students who practiced recall did better than students who built concept maps, even on questions that asked them to make inferences (Karpicke & Blunt, 2011).

How to do it: write or say the answer before you look, then check. Keep going until you’ve recalled each idea correctly at least once, and ideally again on another day (Dunlosky, 2013).

Spacing: spread it out

Spacing earned its high rating because it helps so many kinds of learners (Dunlosky et al., 2013). How far apart should sessions be? A meta-analysis covering 317 experiments found that the best gap grows as the time you need to remember grows (Cepeda et al., 2006). A follow-up study with more than 1,350 people put rough numbers on it. For a test one week away, the best gap was about 20 to 40% of that week. For a test one year away, it was about 5 to 10% of the year (Cepeda et al., 2008). That works out to a review a day or two later for next week, or a few weeks later for something you want to keep all year.

Interleaving: mix it up, for the right material

Interleaving means mixing related types of problems or examples instead of finishing one type before starting the next. A 2019 meta-analysis of 59 studies found a moderate benefit overall. The benefit was largest for paintings and other visual material and small for math problems. For expository texts the results were unclear, and for word lists, blocked practice actually did better (Brunmair & Richter, 2019). So mix things when you’re learning to tell categories apart, like problem types or artists’ styles.

Interleaving often feels worse than it is. In one study, people rated blocked study as more effective even after their own test scores showed that mixing worked better (Kornell & Bjork, 2008).

Elaboration: ask why

Elaborative interrogation means asking yourself why a stated fact is true. Self-explanation means connecting new information to what you already know (Dunlosky, 2013). Both earned moderate ratings. The evidence is promising but thinner than for testing and spacing (Dunlosky et al., 2013).

What works less well

Most students say they reread and highlight, but these techniques don’t reliably boost performance. The 2013 review recommends swapping in better ones, such as practice testing in place of rereading (Dunlosky et al., 2013). Highlighting can be a starting point, as long as more effective strategies follow it (Dunlosky, 2013).

Two later findings complicate this picture without overturning it.

How weak are the low-rated techniques?

A 2021 meta-analysis of the same 10 techniques covered 242 studies and 169,179 participants. It confirmed that distributed practice and practice testing work best. It also found that highlighting and summarization, the weakest, still had fairly high effects, and it warned that most studies measured factual recall rather than deeper understanding (Donoghue & Hattie, 2021). So the low-rated techniques aren’t useless, but testing and spacing give you more for your time.

Do students really rely on rereading?

A 2009 survey of 177 college students found that most repeatedly read their notes or textbook and few tested themselves (Karpicke et al., 2009). A 2019 reexamination argued that the survey’s “restudying” category lumped many strategies together. When students were asked in more detail, only a few preferred rereading early on, almost all switched to self-testing later, and the rereading they did was mostly of parts they hadn’t understood (Kuhbandner & Emmerdinger, 2019). The newer study changes the picture of how students study, but the experiments showing that testing beats rereading still stand.

What about learning styles?

A review commissioned to test them found no adequate evidence that matching instruction to a person’s preferred style improves learning (Pashler et al., 2008).

A simple plan for learning a new subject

1. Get the big picture once. Read or listen to a short overview. One pass is enough, so don’t reread it yet.
2. Turn it into questions. Write questions on the key ideas and answer them from memory before you check. Questions where you have to produce the answer beat multiple choice (Rowland, 2014).
3. Check and fix. Compare your answers with the source and retest what you missed until you get it right (Dunlosky, 2013).
4. Ask why. For each main idea, explain why it’s true and how it connects to something you already know.
5. Space your reviews. Quiz yourself again in later sessions, matching the gap to your goal: a day or two for something you need next week, a few weeks for something you want to keep all year (Cepeda et al., 2008).
6. Mix it up once you have the basics. Practice different problem types or examples together.
7. Trust your scores, not your gut. Rereading and blocked practice can feel like learning when they aren’t (Roediger & Karpicke, 2006; Kornell & Bjork, 2008). This is a cousin of the overconfidence described in our guide to the Dunning-Kruger effect.

Before you trust a book, course or video, check where it comes from with our guide on how to evaluate sources.