This monograph, done in Helsinki, Finland, contains the first and fourth sections dealing with design, hypotheses, results, and discussion, describing school achievement in terms of ability, trait, situational, and background variables. The report (1) investigates the structure of school achievement, (2) describes school achievement in terms of selected personality variables, and (3) applies multidimensional statistical operations in situations where it is desirable to reduce the number of dimensions and to describe a set of dependent variables in terms of a set of independent variables in a single operation. Subjects were school pupils, years seven and eight (184 girls and 150 boys). Sex and performance constancy differences were found relating intelligence to achievement. Several significant correlations were found between dexterity and achievement variables, and again with sex differences. No hypotheses were advanced relating persuasibility to achievement, although small interrelations were demonstrated. Results on teacher ratings were mixed and equivocal. Attitudes were shown to be related to achievement variables, as were several sociometric variables. Relationships between variables of social status and achievement, and between sibling number and achievement were mixed, and differed between sexes. (BP)