In this paper author intends to elucidate epistemologically the concept of the model as the method of science and the role of the model in the cognitive development. The paper is divided into four parts。In the first, the concept and the role of the model are discussed on the view point of materialism, especially on the dialectical one. In the second, with an analysis of L. Wittgenstein's logical atomism and with the historical examination of positivism, the concept of the model in the analytical philosophy is discussed. In the third, author points out some unfavorable phenomena. One of them is that many students of high school seems to think atom and molecule as imaginary and regard the concept of particles as only an instrument for working out the question。When the models destitute of reality such as functional models are used with excess, students may feel that atom, molecule, and ion exist only in imagination. More generally speaking, author wishes to propose that this sort of recognition by the students has been formed in the teaching science based on the positivism, especially on the logical Positivism。The philosophical base of model seems to produce an effect upon the students’ attitude of mind toward the science. As a conclusion of this part, the following rules are laid down which an instructor ought to observe when he uses models in science teaching。1) To use models modestly. 2) To choose indispensable models which are realistically drawn by using the latest knowledge of modern science. L. Pauling’s "electron cloud" model is the typical instance of this. 3) To keep it in mind that symbol of chemical element, molecular formula, structural formula, stoichimetrical equation, and so on should be used as the symbol model, 4) To be temperate in using the various kinds of models in order to prevent the students from the false images of nature. We find this rule in such books as "Teaching Chemistry with Models" by R. T. Sanderson. In the last, the papers on the models in science teaching, which have been published in U.S. and Europe, are summarized and reviewed.

In this report the author intends to analyze the factors which control the effectiveness of biology teaching in the senior high schools in terms of the behavioral objectives and the criterion referenced evaluation 1. First of all, the author tries to realize the difficulties and real status in high school biology teaching which goes on in Japan。2. Then, the author tries to construct the standard idea about the conceptual scheme of biology based on the materials from the reports of the conferences held in 1966 under the direction of the Ministry of Education. 3. The author writes down the conceptual objectives for high school biology in behavioral terms through the full range of the course, which are based on the conceptual scheme mentioned above and also on the modern biology. 4. The author suggests a series of course of study which consists of pretests, work sheets, post tests and supplementary learning guides. 5. Ten different units are tried out through a year。 The data obtained are treated with the computor. 6. Main outcomes of this study are summarized as follows: a. To develop teaching materials for mastery learning of biology b. To provide behavioral objectives through the full course of biology c. To suggest an effective way to evaluate the achievement of every student and of all students d. To suggest the value coeficient which is expected to be used as a measure of the effectiveness of learning This report is only an outline of this study. More details will be described in the following papers.