In 1953 Skinner visited his daughter ’ s maths class. The Harvard psychologist found every pupil learning the same topic in the same way at the same speed. A few days later he built his first " teaching machine ", which let children tackle questions at their own pace. By the mid- 1960 s similar gizmos were being flogged by door-to - door salesmen. Within a few years, though, enthusiasm for them had fizzled out.
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