Reasoning about certainty and uncertainty in concrete, causal, and propositional contexts.

The present study examined children's comprehension of certainty and uncertainty within the context of concrete and propositional reasoning tasks. First, third, and fifth graders were given PierautLeBonniec's (1980) box task and a multisufficient causality task to assess reasoning about certainty and uncertainty in concrete contexts. Children were also given conditional syllogisms to assess this ability in a propositional context. Half of the children at each grade were given contramanded syllogism task statements intended to block erroneous conversational inferences made about these conditional statements. Results indicated no developmental differences in reasoning about concrete certainty, but significant improvement occurred in reasoning about concrete uncertainty. On syllogisms, only the fifth graders benefitted from contramanding so as to demonstrate an understanding of propositional uncertainty. Correlational and error analyses showed that the discrimination between certainty and uncertainty is mastered in concrete contexts prior to the time when this discrimination occurs in propositional contexts. These findings support the position that reasoning about concrete certainty and uncertainty requires a different competence than that required for reasoning about propositional certainty and uncertainty.