Questions versus statements: challenging an assumption about semantic illusions.

In previous semantic-illusion research the tacit assumption has been that questions and statements-to-be-verified of similar semantic content lead to a similar proportion of semantic illusions. This assumption was made despite the fact that questions are thought to have different processing demands from those of statements. This paper presents empirical evidence that questions tend to lead to more semantic illusions than do statements-to-be-verified. Two experiments were carried out to provide a direct comparison between the semantic-illusion rates for statements and for questions. In Experiment 1, open-ended questions led to significantly more semantic illusions than did true/false statements. Experiment 2 replicated this effect using multiple-choice response options in the question condition. It is concluded that the syntactic form of a sentence affects the way in which semantic information is processed, and the implications of the findings are discussed.