The latent structure analysis that was originally devised for the measurement of social attitudes can be applied to the study of mental development. Using the latent class model, one of the models of the latent structure analysis, we can hope to find the latent classes or genotypes underlying in a given population or group.Knowing the number and properties of types at several age levels, we can see the differentiation process along with age increment. By analyzing the behavioral data pool gathered from several age levels, we can also hope to find the types corresponding to the critical developmental stages. This writer has already reported that the data concerning the interests of first, third, and fifth graders of elementary school by inventory was analyzed by the latent class model.It was found that in each grade pupils were divided into two latent classes, where one of the two classes was the masculine type of interest and the other was the feminine type of interest. This article reports the results that were obtained by analyzing the above data from several different points of view.The data pool obtained from first, third, and fifth graders was analyzed in order to find the interest types that correspond to the critical stages of mental development.Although the subjects and data analyzed here are the same as cited above, it will be repeated.The subjects were 270 pupils attending the elementary school attached to the Hirano Branch of Osaka Gakugei University. The interest inventory that was prepared for this research consisted of about 200 items, and Ss answered them by marking one in the Like-Dislike-Indifferent scale (e.g.In team play, how do you like to be the boss?-L-D-I).Answers were dichotomized before analysis.On the basis of each item's retest reliability (using a point correlation coefficient), with a 20-30 day testing interval, 45 items were selected and analyzed by the the latent class model. Analysis I.Answers obtained from 270 pupils of the first, third, and fifth grades were analyzed after the general solution of B.F.Green, Jr., with some minor changes.Two latent classes were found: the masculine type of interest and the feminine type of interest but the types corresponding to the critical developmental stages were not found. Analysis IIA.Data from 160 boys of first, third, and fifth grades which were analyzed.Two latent classes were identified, which were interpreted as the lower grader's masculine type of interest and the higer grader's masculine type of interest. Analysis IIB.Data from 110 girls of first, third, and fifth grades were analyzed, and two latent classes were also found: The lower grader's feminine type of interest and the higher grader's feminine type of interest. In addition, some evidence indicates that the “Type I” found in “Analysis I” rather represents the higher grader's masculine type, and that “Type II” found in “Anlysis I” rather represents the lower grader's feminine type.Sc, it may be said that the higher grader's masculine type and the lower grader's feminie type are more fundamental types of interest and the lower grader's masculine type and the upper grader's feminine type are less fundamental. Therefore the two types which were found in “Analysis I” and which were named as masculine and feminine types are considered as a composite of two sub-types.
The purposes of this study were (a) to consider Jean Piaget's theory on conservation (especially conservation of liquid and weight), and (b) to analyse the role or meaning of nonconservation. Hypotheses: (1) Even if the child does not exhibit conservation in Piaget's classic experiments, we cannot say that he has no conservation.(If we admit, as Piaget, that the child cannot acquire conservation without logical multiplication or conceptual coordination, we must reject our hypothesis.) 2) Because of perceptual and (other conditions inhibiting the child from exhibiting conservation, the child who has acquired conservation cannot exhibit conservation if conditions change. Procedure: Our Subjects were 71 primary school pupils (6-9 years old). 1) Piaget's classic ex (periments of conservation 2) Conservation of liquid by usin g screened beakers: Two standard _beakers are partly filled so that the child judges them to contain equal amounts of water.Another beaker which is hidden by a screen except for the top is introduced.The Experimenter pours from a standard beaker into the screened one.Then the child is asked which has more to drink, or do they have the same amount. (3) Quantification of liquid: Two beakers, A and B (A is wider than B) are partly filled, and two empty beakers (one is identical with B and the other is smaller than A and B in both height and width) are introduced.The child is asked,“Which has more to drink, A or B?”, and informed,“If you want to use these empty beakers, you may use them.” Results: (a) In comparison with the classic experiment, there is a striking increase in correct equality judgment in the screened experiment.(b) Without a concept of conservation, it is impossible for the child to quantify liquid.(c) The child justifies his correct judgment not by logical multiplication but by noting that “You only poured it” or “Its the same water.” (d) When the child acquires conservation and his concept of conservation is f ixed to some extent, he exhibits nonconservation. Judging from out results, we cannot explain result (a) and (d) by Piaget's theory.The child discovers essential causality by falling into nonconservation. In this way, he generalizes and develops his concept of conservation, and in this sense, the role of nonconservation is very important for the development of concept of conservation.