To help educators obtain more specific comparative data on preschool programs, this paper develops some common constructs for the objective assessment of any program. The constructs proposed are: (1) density, the total amount of sensory stimulation encountered within a given time span; (2) variety, the extent to which the program provides encounters to diverse stimuli/situations; (3) complexity, the extent to which children encounter stimuli/situations in their natural complex state as compared with encountering prepared simplified versions; (4) sequence, provision for future encounters and/or emphasis given to previous experience; (5) regularity, the extent to which a pattern of encounters recurs on a daily or weekly basis; (6) emergence, extent to which new materials are introduced as the program progresses and/or which expectations for use of materials and interactions are altered during the program; (7) uniformity, extent to which children within a program have similar encounters; (8) contrast; (9) pacing; (10) scope, and (11) controllability. The consideration of dimensions would facilitate the combination of various aspects of several programs to produce programs more closely tailored to a child's assessed personological characteristics or stage of development. (Author/AJ)