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Judging the strength of designated evidence
Author(s) -
Briggs Laura K.,
Krantz David H.
Publication year - 1992
Publication title -
journal of behavioral decision making
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 76
eISSN - 1099-0771
pISSN - 0894-3257
DOI - 10.1002/bdm.3960050202
Subject(s) - psychology , construct (python library) , empirical evidence , social psychology , fallacy , cognitive psychology , computer science , epistemology , philosophy , programming language
Judgments of evidence strength were obtained in a series of vignettes, each containing one or two items of evidence for each of two logically independent hypotheses. Each judgment concerned a designated subset of the presented evidence. Different groups of subjects encountered different but overlapping sets of evidence. We compared groups that judged the same designated evidence for the same hypothesis, but differed in exposure to surrounding (nondesignated) evidence. Results showed clear separation of relevant from irrelevant evidence and of designated from surrounding relevant evidence. This was particularly clear in the second experiment, where judgments of designated evidence remained invariant whether the surrounding evidence supported or contradicted the specified hypothesis. The conjunction fallacy was observed for judgments of evidence strength, but was substantially reduced by a simple instruction. Because subjects can separate evidence, it becomes possible to construct cardinally scaled standards of evidence strength using conjoint‐measurement methods.