Perception as a possible source of conservation: evidence for length conservation

In conservation problems, it is commonly assumed that equivalence judgments are not facilitated by observation of the stimuli following transformation. The reverse is usually assumed to be the case. These assumptions were tested in a training experiment. Perceptual counterparts of a series of conservation of length tests were presented to subjects who were catagorized as conservers or nonconservers on conservations of length pretests, and to conservers and nonconservers given conservation of length training. Perceptual performance of the untrained nonconservers was significantly worse than that of the other 3 groups, that is, trained nonconservers, untrained conservers, and trained conservers. These findings are interpreted as consistent with the hypothesis that conservation is attained with the support of perception, not in spite of it.