Linguistic and logical factors in recognition of indeterminacy
People, especially children, have difficulty recognizing cases of logical indeterminacy, that is, when no conclusion is logically warranted by the available evidence. This article examines the contribution of logical and linguistic factors to this phenomenon. Three experiments were conducted with second- and thrid-grade children. In each, subjects were given an initial premise sentence that partially described a set of invisible objects. Subjects were then presented with probe sentences referring to the objects and asked to tell whether each probe statement was logically true, false, or indeterminate given the premise. The first experiment examined two linguistic factors: the lexical embodiment of the relevant logical information in the probes (modal verb vs. copula), and the discourse level of the response (question-answering vs. truth-value judgment). Neither variable significantly reduced the difficulty of recognizing indeterminacy, indicating that, contrary to recent speculations, the logical form of the inference, rather than other linguistic aspects, is implicated in their difficulty. The next two experiments examined whether a task variable designed to reduce the complexity of the inferential process (while leaving the initial mental representation of the problem unchanged) would improve recognition of indeterminacy. This variable was highly effective, most importantly so in subjects with a fragile understanding of indeterminacy. It is argued that logical knowledge has both a representational and an executive function: It operates in generating the initial representation of the logical information, and in the executive monitoring of the subsequent inferential process. The difficulty of indeterminate inferences is task-dependent in its degree and presumably due, to a large extent, to the executive factor. © 1989.
Falmagne, Rachel Joffe; Mawby, Ronald A.; and Pea, Roy D., "Linguistic and logical factors in recognition of indeterminacy" (1989). Psychology. 813.