Study may, then, be classified according as the response required is physical habit, memory, appreciation, or judgment. These types overlap, no one of them can exist absolutely alone, but it is possible to name them according to the response. Study may also be classified into supervised study, or unsupervised study, into individual or group study. We might also classify study as it has to do with books, with people, or with materials. The term has been rather arbitrarily applied to activities that dealt with books, but surely much study is accomplished when people are consulted instead of books, and also when the sources of information or the standards are flowers, or rocks, or textiles. Study, then, is a big term, including many different varieties of activities, of varying degrees of difficulty and responsibility. It cannot possibly be taught all at once, according to one method, at one spot in the school curriculum. Power to study is of very gradual growth. It must proceed slowly, from simple to complex types. From easy to difficult problems, from situations where there is close supervision and direction to situations where the student assumes full responsibility. Knowing how to study is not an inborn gift--it does not come as a matter of intuition, nor does it come in some mysterious way when the child is of high school age. It is governed by the laws of learning, or readiness, exercise, and effect, just as truly as any other ability is. If adults are to know how to study, if they are to use the technique of the various kinds of study efficiently, children must be taught how. Nor can we expect the upper grammar grade or the high school teachers to do this. Habits of study must be formed just as soon as the responses to which it leads are needed. Beginning down in the kindergarten with study in connection with physical and mental habits, the child should be taught how to study. The type must gradually become more complex; he must pass from group to individual study, from supervised to unsupervised, but it must all come logically, from step to step. True, it is not easy to teach how to study. A careful analysis of the various types with their peculiar elements should be a help. First, however, there are some general principles that underlie all study which must be discussed.