ABSTRACT
Introduction To look for evidence and to weight it is an important requirement needed to solve a problem and, in general, to think. According to Baron (1990) 'thinking is a conscious response to doubt' (p. 29). This means 'we may analyze all thinking into search and inference: we search for possibilities, evidence and goals. Possibilities are possible answers to my question ... Evidence is anything I use to decide among the possibilities ... Goals are the criteria I use to weight the evidence' (p. 29). And he continues:
The use of evidence, in light of goals, to strengthen or weaken possibilities, is inference. Inference relies on heuristics and other kinds of rules. Inference is only part of thinking, however, the rest is search. (Baron, 1990, p. 29)
This remark seems to us to show very clearly how relevant to the study of thinking and problem solving is the study of how people search for, select, evaluate and use evidence to make a decision or to solve a problem. Especially in the case of ill-defined problem solving - as is the case in most of the situations in everyday life - the possibilities, Baron referred to, are many and, therefore, the process of searching becomes more important. A second step would be to use the evidence to make inferences. But how the evidence is used depends on how the information presented is interpreted and evaluated by the subject.
