should have relation to a personal problem, (iii) The material furnished by way of information should be relevant to a question that is vital in the student's own experience. What has been said about the evil of observations that begin and end in themselves may be transferred without change to communicated learning. Instruction in subject-matter that does not fit into any problem already stirring in the student's own experience, or that is not presented in such a way as to arouse a problem, is worse than useless for intellectual purposes. In that it fails to enter into any process of reflection, it is useless; in that it remains in the mind as so much lumber and débris, it is a barrier, an obstruction in the way of effective thinking when a problem arises.
and to prior systems of experience Another way of stating the same principle is that material furnished by communication must be such as to enter into some existing system or organization of experience. All students of psychology are familiar with the principle of apperception—that we assimilate new material with what we have digested and retained from prior experiences. Now the "apperceptive basis" of material furnished by teacher and text-book should be found, as far as possible, in what the learner has derived from more direct forms of his own experience. There is a tendency to connect material of the schoolroom simply with the material of prior school lessons, instead of linking it to what the pupil has acquired in his out-of-school experience. The teacher says, "Do you not remember what we learned from the book last week?"—instead of saying, "Do you not recall such and such a thing that you have seen or heard?" As a result, there are built up detached and independent systems of school knowledge that inertly overlay the
