Children's overestimation of the knowledge to be gained from seeing

In three investigations children aged 4-9 years were given a sequence of trials on each of which they experienced pairs of objects which looked the same but felt different (such as full and empty cereal packets) or felt the same and looked different (such as chocolate bars with different coloured wrappers). On each trial the experimenter chose one of the items from a pair and children predicted whether they themselves, or another person or doll, would know which one it was just by seeing it. In two of the three investigations, even the youngest children showed clear evidence of discriminating in their knowledge judgments between the two types of pairs, but nevertheless children frequently overestimated the knowledge to be gained from seeing. Errors of overestimation when the visual input was ambiguous as to feel were correlated with those made when the visual input was ambiguous as to size, suggesting the children's problem was not specific to understanding about the modality-specific aspect of knowledge. Furthermore, making it easier for children to isolate the visual input from an object from the non-visual was ineffective in reducing errors of overestimation. These results provide no evidence that children had difficulty imagining or isolating the visual aspect of the chosen object, but suggest that they may fail to realize when the input is ambiguous.