How to remember what you read: what the research supports

What the research rates highest

In 2013, Dunlosky and colleagues reviewed 10 common learning techniques and rated how useful each is. Practice testing and distributed practice received high utility ratings because they help learners of different ages and abilities, across many tasks and in real classrooms.

Elaborative interrogation, self-explanation and interleaved practice were rated moderate, since the evidence was more limited. Summarization, highlighting, the keyword mnemonic, imagery for text learning and rereading were rated low. Most of this work studied students, not general book readers, so treat it as the best evidence available, not a promise.

• High: practice testing, distributed (spaced) practice.
• Moderate: elaborative interrogation, self-explanation, interleaved practice.
• Low: summarization, highlighting, keyword mnemonic, imagery, rereading.

Retrieval: test yourself, do not just reread

In a 2006 experiment, students studied prose passages and then either took recall tests or restudied the material. After 5 minutes, restudying gave better recall. After 2 days and after 1 week, the students who had been tested remembered substantially more, even though restudying made them feel more confident.

For a book, that means closing it and writing down what you remember before you look again. Feeling that you know a chapter is not the same as being able to recall it.

Spacing: come back after a day, a week, a month

Forgetting is fast at first. A 2015 replication of Ebbinghaus’s forgetting curve tested relearning after 20 minutes, 1 hour, 9 hours, 1 day, 2 days and 31 days, and found a curve similar to the original data. That study used a single subject learning lists, so it is a picture of forgetting, not a study of books. It also found the curve is not perfectly smooth, with a rise from the 24-hour point.

Spaced practice is the other technique rated high by Dunlosky’s team. The practical rule is to review soon, then again after longer gaps. A gap of a day, then about a week, then about a month is a reasonable schedule, though the sources do not prove those exact intervals.

Why highlighting and rereading are weak

The review notes that most students report relying on rereading and highlighting, yet the authors rated both low utility because they do not consistently boost performance, and recommend practice testing in place of rereading.

Highlighting marks what you found interesting while you read. It does not make you retrieve anything later. If you like to highlight, use it as a way to pick the three ideas you will test yourself on.

A 10-minute weekly routine for books

Right after a reading session, close the book and write the main idea of the chapter in a sentence or two, plus one example and one thing you could do. Then open the book and check what you missed. That takes about 3 minutes.

Once a week, take 10 minutes. Without looking, write what you remember from each book you are reading, then check. A day or so later, review the ones you missed. Every month, pick the single idea you most want to keep and use it in a conversation or a decision.

• After each session: close the book, recall, then check.
• Once a week: 10 minutes of recall across your books.
• Once a month: pick one idea and act on it.

Where short lessons fit

Not every book deserves the routine. Pick the ones whose ideas you want to use, and give the rest a lighter pass. A few ideas remembered well are worth more than many skimmed. A short lesson can be a good first pass, because it gives you the structure before you commit to the whole book, and a quick second pass on an idea you want to keep. Reading a summary does not replace the recall step, and a summary is not the same as the book.

IQumi lessons are written to carry one idea, one concrete example and one takeaway, and they take under a minute. After a lesson, put it away and write the idea down yourself.