Studies of the hierarchical attainment of conservation of physics concepts revealed significant differences with respect to age, sex, and grade level in a random sample of seventh and eighth grade students. Conservation of a quantity did not necessarily depend on the prior conservation of its constituent fundamental quantities. (MLH)

Empirical data relate to Bruner's and Ausubel's theories of learning concepts at different age levels. The concept of vector addition was taught to eighth, ninth, and tenth grade students. The concept was learned and retained by high ability ninth and all tenth grade students. (PS)