=Question and Answer.=--On account of the large use of questioning as a means of directing and testing the pupils' selecting of old knowledge, or interpreting ideas, the developing method is often identified with the question and answer method. But the real mark of the developing method of teaching is the effort of an instructor to assure himself that, step by step, throughout the learning process, the pupil himself is actively apprehending the significance of the new problem by a use of his own previous experience. It is true, however, that the method of interrogation is the most universal, and perhaps the most effective, mode by which a teacher is able to assure himself that the learner's mind is really active throughout each step of the learning process. Moreover, as will be seen later, the other subsidiary methods of the developing method usually involve an accompanying use of question and answer for their successful operation. It is for this reason that the question is sometimes termed the teacher's best instrument of instruction. For the same reason, also, the young teacher should early aim to secure facility in the art of questioning. An outline of the leading principles of questioning will, therefore, be given in Chapter XVIII. =Other Forms of Development.=--Notwithstanding the large part played by question and answer in the developing method, it must be observed that there are other important means which the teacher at times may use in the learning process in order to awaken clear interpreting ideas in the mind of the learner. In so far, moreover, as any such methods on the part of the teacher quicken the apperceptive process in the child, or cause him to apply his former knowledge in a more active and definite way to the problem in hand, they must be classified as phases of the developing method. Two of these subsidiary methods will now be considered. THE OBJECTIVE METHOD =Characteristics of the Objective Method.=--One important sub-section of the developing method is known as the objective method. In this method the teacher seeks, as far as possible, (1) to present the lesson problem through the use of concrete materials, and (2) to have the child interpret the problem by examining this concrete material. A child's interest and knowledge being largely centred in objects and their qualities and uses, many truths can best be presented to children through the medium of objective teaching. For example, in arithmetic, weights and measures should be taught by actually handling weights and measures and building up the various tables by experiment. Tables of lengths, areas, and volumes may be taught by measurements of lines, surfaces, and solids. Geographical facts are taught by actual contact with the neighbouring hills, streams, and ponds; and by visits to markets and manufacturing plants. In nature study, plants and animals are studied in their natural habitat or by bringing them into the class-room.