Mental representation and hypothetico-deductive reasoning: The case of the THOG problem

Abstract

This article reports three experiments that deal with the source of the difficulty of Wason's (1977) THOG problem. The solution of this problem demands both the postulation of hypotheses and a combinatorial analysis of their consequences. Experiment 1 showed that the generation of the hypotheses is not in itself sufficient to solve the problem. Experiment 2 showed that a version presenting a plausible context for separating the level of data from that of hypotheses produced a better performance than both the original abstract version and a thematic version lacking the plausible context separating the levels. Experiment 3 gave evidence that this context can produce facilitation even with the geometric material of the classic version. This experiment also showed that a pictorial presentation of data and a verbal presentation of hypotheses affect performance negatively. The results demonstrate the role of problem representation in problem solving, and, in particular, the role of homogeneity in representing data and hypotheses in hypothetico-deductive reasoning.

Using dual-process theory and analogical transfer to explain facilitation on a hypothetico-deductive reasoning task

“…The difficulty emanating from the THOG problem seems to occur in response to working memory overload. When participants are tasked with generating hypotheses and holding them in memory while testing the three possible THOGs, working memory capacity is exceeded and confusion results (Girotto & Legrenzi, 1989;Newstead & Griggs, 1992). In response to this confusion, participants may simplify the task by assuming that the features of the identified THOG are the features that have been written down.…”

“…Most participants understand the exclusive disjunctive rule (e.g., Wason & Brooks, 1979), can generate hypotheses for the possible combinations (e.g., Girotto & Legrenzi, 1989;Smyth & Clark, 1986), and are able to test the figures against these hypotheses (Wason & Brooks, 1979). The difficulty of the problem, however, results from the necessity of carrying out all of these tasks together.…”

“…The difficulty of the problem, however, results from the necessity of carrying out all of these tasks together. Girotto and Legrenzi (1989) suggested that participants have difficulty separating the features of the exemplar from the features that may have been written down. Newstead and Griggs (1992) elaborated on this explanation and labeled it ''confusion theory''.…”

“…Specifically, participants often identify the black circle and white square as THOGs and the white circle as not a THOG (labeled Intuitive error A by Griggs & Newstead, 1983) or they judge the THOGness of the black circle and white square as indeterminate but decide the white circle is not a THOG (labeled Intuitive error B by Griggs and Newstead). The ''confusion theory'' explanation for THOG task performance has garnered substantial support from investigations demonstrating the facilitating effect of separating the features of the exemplar from the features of the hypothesized combinations (Girotto and Legrenzi, 1989;Needham and Amado, 1995;O'Brien, Noveck, Davidson, Fisch, Lea, & Freitag, 1990), thus reducing the frequency of intuitive errors.…”

Elementary, my dear Wason: The role of problem representation in the THOG task

“…Because the solution of the problem requires the postulation of hypotheses and a combinatorial analysis of their consequences in a state of uncertainty and because the problem has proved to be very dicult, the THOG problem has been of great interest to reasoning researchers for the past two decades. Not only do most experimental participants (usually >80%) fail to solve the problem (Newstead, Girotto, & Legrenzi, 1995), but most experimenters have also failed in their attempts to improve such performance without major changes in problem presentation (e.g., Girotto & Legrenzi, 1989 or structure (e.g., Griggs & Newstead, 1982). The present study addressed the latter failure.…”