Facilitation of Conservation of Number in Young Children.

Nursery school children (N=64) received seven tests of conservation of number which varied in the type and number of perceptual supports for conservation. Most of the tests with these supports facilitated performance in comparison to the standard conservation test. Conservation appeared earlier than usual. There were significant effects of supports which emphasized correspondence and deemphasized length cues, unclear effects of the number of objects, and no effect of interest value of the stimuli. There was a set effect; i.e., beginning with the easiest test produced more conservation overall than did beginning with the most difficult test. It was proposed that the development of conservation involves several levels, varying from an early rudimentary understanding of invariance to the final, mature conception of number. (Author/SET)