An often repeated but, if you stop to think about it, somewhat bizarre finding from research on tutoring is that the experience and training of the tutor don’t make much difference to how well students learn.

That doesn’t mean you can take someone off the street and feel confident they will be as successful as anyone else. Just as in any walk of life, some people really are better at tutoring than others. But neither their experience in the subject they are teaching (above a minimum level), their experience of tutoring, nor the training they received tell you whether a new tutor will be successful when faced with real students.

This seems like a critical gap in our understanding of tutoring, an approach that has become a significant element of K-12 education since the global pandemic. It is not the only gap, as we shall see. In fact, it often seems that the only things we know for sure about tutoring are that it works and it’s expensive ¹.

This odd result about tutor experience dates back to a 1982 meta-analysis by Peter Cohen of Dartmouth College. A meta-analysis assembles findings across a set of research studies and aggregates them. Cohen took studies in which tutors received training, for instance, and compared them with studies in which they did not. He found that, on average, the amount of students' learning between the two sets was the same. There does not appear to have been further investigation of the question in the 40 years that followed.

And yet, something must be making some tutors better than others, which, as anyone who has been tutored can tell you, they are. What is it? Can it be distilled, bottled, and delivered to newly recruited tutors for their nourishment? If so, we could provide the elixir to any group of tutors, re-run Cohen, and prove him wrong. With this, we will have founded the science of tutoring.
        This book explores that wild idea.

Tutoring is as old as the ancients: Aristotle himself tutored Alexander the Great. Even older, in fact: bees, ants, pied babblers, and cheetahs all tutor, in the sense that they modify their behavior to help others learn without an immediate benefit to themselves. Adult meerkats consume prey as soon as they catch it. But if their pups are watching, they disable the prey so that the youngsters can practice killing—it for instance, the adult might remove the sting from a scorpion. As the pups age, they are given increasingly intact prey. In the language of tutoring, meerkats “scaffold” learning and “fade” the scaffolding over time. If pups struggle, adults help more.

But tutoring is not universal. Our closest relatives, chimpanzees, don’t appear to do it. And, according to Kevin Laland, an evolutionary biologist, “there is surprisingly little evidence of teaching among modern-day hunter-gatherers, in comparison to learning by imitation.” But it is difficult to imagine modern human society as having arisen without tutoring and, later, school teaching. Schools, being the cheaper option, overtook tutors as the main source of education in England during the reign of Elizabeth I. But tutoring never went away and, indeed, is resurgent, driven by distrust toward schooling, an increasingly desperate need to keep kids on track academically, and a growing recognition of individual differences.

Despite its long history, tutoring is something of an enigma. There is strong evidence for its remarkable effects: when you add tutoring to a student’s education mix, they gain a greater understanding, are more motivated, and work faster. But we don’t know why or how. What are the active ingredients of tutoring? Without an answer, we know neither how to train new tutors most effectively nor what aspects of tutoring we can vary without doing violence to it. For example, why does tutoring work for a group of three tutees but not for thirteen, or thirty? Does tutoring work as well when the tutor is remote? Can computers be used to tutor or at least to aid human tutors? If so, in what ways?

As with many advances in our understanding of a subject, a crucial step is to generate higher-resolution data and look at it closely. Understanding disease and cell biology mostly happened through guesswork until the invention of the microscope. Understanding the movement of celestial bodies was mostly guesswork too until the invention of the telescope ².

Tutoring finally got its invention-of-the-microscope moment in the 1990s. A few researchers began to record tutoring sessions, transcribe them, and look for common “moves” such as tutor-gives-explanation, tutor-asks question, student-answers-question, and tutor-gives feedback. Once you have painstakingly coded enough transcripts, you can ask “Which moves predict student learning?” For instance, do tutoring sessions with a lot of tutor-gives-explanation moves result in more learning than those without?

Still, in a country with thousands of education researchers, it is curious that so few of them have turned their attention to tutoring. With the manual transcription and coding of tutoring sessions—and more recently, semi-automatic transcription and coding—studying the science of tutoring is becoming possible. What researchers are finding is not what you might have expected.

This is not a book about how to organize and run a tutoring program, any more than a book on aeronautics is about how to organize and run an airline. Certainly, if you are to run an airline, you will want to be sure that the people who designed your airplanes know a great deal about aeronautics. And the more your pilots know of it, the better. But you don’t need to. So, this is a book for people who design tutoring programs and for the tutors themselves, people who need to know how and why tutoring works.

There are many excellent books and courses on the science of flight. But to my knowledge, there are none at all on the science of tutoring. Given the enormous surge in tutoring happening around the world, that is a problem—one tantamount to dozens of airlines starting up without anyone really knowing how to keep planes in the air. This book attempts to fill that—gap or at least to begin to fill it.