how we learn – review

How We Learn by Benedict Carey is focused mostly on memory and learning for recall but it is a good read and there is likely something new about learning here for anyone. Carey is a journalist who went through much of the research on memory in order to make sense himself. By synthesizing and comparing the research on memory and learning, he has done a great service to the non-academic.

One of the first principles discussed is how memory works: “Any memory has two strengths, a storage strength and a retrieval strength.”

‘Yet there are large upsides to forgetting, too. One is that it is nature’s most sophisticated spam filter. It’s what allows the brain to focus, enabling sought-after facts to pop to mind … “The relationship between learning and forgetting is not so simple and in certain important respects is quite the opposite of what people assume,” Robert Bjork, a psychologist as the University of California, Los Angeles, told me. “We assume it’s all bad, a failure of the system. But more often, forgetting is a friend to learning” … Using memory changes memory — and for the better. Forgetting enables and deepens learning, by filtering out distracting information and by allowing some breakdown that, after reuse, drives retrieval and storage strength higher than they were originally.’

Carey, paraphrasing Louis Pasteur, says that, “Chance feeds the tuned mind”. When we are tuned to a problem or topic, our mind sees more related cues. “When we are working on a paper about the Emancipation Proclamation, we’re not only tuned into racial dynamics on the subway car, we’re also more aware of our reactions to what we’re noticing.”

Carey also debunks the power of focused repetition (drill & practice), upon which much formal education and training is based. The research he reviewed shows that ‘interleaving’ (mixing related but distinct material during study) is more powerful. “The mixing of items, skills, or concepts during practice, over the long term, seems to help us not only see the distinctions between them but also to achieve a clearer grasp of each one individually. The hardest part is abandoning our primal faith in repetition.” He concludes that interleaving is “preparing the brain for the unexpected”.

Another powerful principle is ‘perceptual learning’ pioneered by Eleanor Gibson in 1969: “We don’t just see, we look; we don’t just hear, we listen. Perceptual learning is self-regulated, in the sense that modification occurs without the necessity of external reinforcement. It is stimulus-oriented, with the goal of extracting and reducing the information simulation.” This is learning without thinking and it seems we do it all the time.

A fairly well known concept in the field of learning is ‘spacing’ made famous by Hermann Ebbinghaus. But his work was based on remembering nonsense syllables, which had no context. Piotr Wozniak looked at spaced practice in learning a new language and developed an algorithm that became a software program called SuperMemo. Carey summarizes the research: “To build and retain foreign vocabulary, scientific definitions, or other factual information, it’s best to review the material one or two days after initial study; then a week later, then about a month later.”

Testing, especially trying to teach what you know to others, is a very powerful learning method. Early testing, before any teaching has happened, can significantly improve learning. In addition, testing can dispel the ‘fluency illusion’ where we think we know more than we do. Testing and teaching ensure that we actually know what we think we know. So don’t save the final exam for the end, give it on day one. Carey explains this from the perspective of writing a long book. “Pretend that the book already exists. Pretend that you already know … Pretend that you already are an expert and give a summary, a commentary — pretend and perform. That is the soul of self-examination” pretending you’re an expert, just to see what you’ve got.”

This is one more resource I would recommend for personal knowledge mastery.