This is Part 2 of 4 of my summary of “How We Learn” by Benedict Carey. Other parts:
Memory strengths: storage and retrieval
The theory of learning states, among other things, that memory has two strengths: storage and retrieval. Once we store something in memory, it is there forever (more or less) – the size of the storage in the brain is more than enough to save every second of one’s life. The learning strength “builds up steadily with studying, and more sharply with use,” and it can only increase. On the other hand, much of learning is about retrieval strength. It is how easily we can remember what we learned or experienced previously. The retrieval strength also increases with studying and with use, however, it drops off quickly without reinforcement. Also, the “capacity [of retrieval] is relatively small, compared to storage. At any given time, we can pull up only a limited number of items in connection with any given cue or reminder.” Improvements to the learning process are then aimed at increasing the retrieval strength, especially long term and as applied to situations and problems that we didn’t study directly (generalization).
The power of forgetting
Think of learning as building a muscle: forgetting is important because “the harder we have to work to retrieve a memory, the greater the subsequent spike in retrieval and storage strength (learning).” The practical use cases of this finding include (more details to follow):
- Spacing of study sessions: let yourself forget some of what you studied to make it harder (but still possible) to retrieve by breaking your study time in multiple sessions.
- Self-testing and testing in general – unaided retrieval of what you’ve already learned is in itself a learning process. In my opinion, this speaks in favor of more tests in school, but only if they are low-pressure, i.e., not carrying the weight of future admissions to the next level of education.
The effect of context on learning
Studies show that changing the context of where and when we learn helps retrieval. For example, contextual cues, such as the place where we study, the background music, the light and color of the environment, weave themselves into the learning and when present again help trigger the memory of what we learned. “We can easily multiply the number of perceptions connected to a given memory — most simply, by varying where we study.”
Breaking up the study time
Spacing out study sessions has been proven to help for improving retention of memorized material. “If the test is in a week, and you want to split your study time in two, then do a session today and tomorrow, or today and the day after tomorrow. If you want to add a third, study the day before the test ( just under a week later ).” The book provides a specific recipe for varying time intervals for preparing for a test. This technique works well for memorizing facts such as foreign languages, names, places, etc.
Testing is learning
Many of us had used a technique when someone is asking us questions about the material that we expect to be on the test, and we try to answer these questions from memory. It turns out that not only the process checks our knowledge, but also by remembering the answers without looking at the notes or textbook, we are improving our retrieval strength of the material. Such testing can be a test given by the teacher or a self-examination, for example, trying to recite a poem by heart. An essential aspect of this process is providing the correct answer immediately or shortly after the test. Many online corporate training programs use this technique (on purpose or not) by providing short quizzes and highlighting correct answers afterward.
Another interesting concept is pre-testing, i.e., testing for something you haven’t learned yet — the mere process of guessing the right answer wires our brains to the material taught after the pre-testing. As a result, we have a much better recall during the tests performed after the learning is complete.
To summarize, “testing does not = studying, after all. In fact, testing > studying, and by a country mile, on delayed tests.”
Teaching someone is an effective learning technique
There is a saying to the effect of “you haven’t learned the subject until you can teach it to others.” Trying to explain to someone what you’ve just learned triggers better learning and elucidates the gaps in your understanding. A long time ago, I read a book about a woman who made a living teaching foreign languages in Poland after World War II. She only knew Polish when she started. She then achieved fluency in seven languages by studying them herself lesson by lesson from books and then teaching the same lessons to her students. She was always just a couple of lessons behind with her students than what she was learning herself. In my own experience, explaining a concept to someone brings clarity that is rarely achieved by just reading about it. By the way, writing this article also has this effect!
Fluency illusion
The fluency illusion is “the belief that because facts or formulas or arguments are easy to remember right now, they’ll remain that way tomorrow or the next day.” When we look at notes, highlighted sections, or outlines, we feel that we know the material. However, when the notes are not available, we can’t remember anything. The illusion is so strong that is it is easy to convince yourself that you are ready for the test if you can recall something you just read. This illusion is a consequence of the fact that “the easier it is to call a fact to mind, the smaller the effect on learning.” Self-examination mentioned above is an ample antidote to the fluency illusion.
The role of sleep
Sleep has a consolidating effect on learning. Experiments showed that people who had a 1-1.5 hour nap or slept overnight between studying and testing performed better on the tests. The book explains the 5 phases of sleep and makes an interesting point that a full cycle nap of 1-1.5 hours was shown to affect learning similar to a full 8-hour overnight sleep. I conjecture that for those pulling all-nighters before the exam, even a couple of hours of sleep can improve the results. “Unconscious downtime clarifies memory and sharpens skills — that it’s a necessary step to lock in both. In a fundamental sense, that is, sleep is learning .”
Next: Summary of “How We Learn” – Part 3: Distraction
All quotes above are from the book “How We Learn“.
Photo by Alexis Brown on Unsplash.