The Wason's selection task: Content effect, instruction effect or both?

This experiment explore the effect of the scenario's availability, instruction (true/false vs. violation) and presentation order on performance in different versions of the Wason's selection task. Each subject was given three problems corresponding to the three different rules's content (abstract version, thematic-lsw and thematic-norm). The main analysses are presented in terms of matching and logical indices (Pollard & Evans, 1987). The matching and logical indices are influenced by content's rule. The performance on the two thematic conditions are influenced by the instructions, but the correct selection is not influenced in the formal version. These results are not consistent with the syntactic theories of the human reasoning and are discussed in terms of the pragmatic and semantic human reasoning theories