ABSTRACT
In chapter 1, we argued that whatever object of learning learners, try to appropriate, certain critical features of that object have to be discerned, that is, learners must learn to see certain situations in certain ways. But learners can never discern anything without experiencing variation. The experience of patterns of variation specific for different objects of learning is a necessary condition for appropriating those objects of learning. If this is true, then successful teachers must be good at constituting such necessary conditions in the classroom, that is, the specific patterns of variation. One of the main points of this book is that we have managed to identify a critical factor in teaching, a factor that distinguishes between teaching that makes a certain learning possible and teaching that fails to achieve this. The empirical comparisons in chapter 3 and chapter 4 demonstrate this in greater detail.
