Organizational Behavior and Human Decision Processes
Vol. 81, No. 1, January, pp. 1–27, 2000
doi:10.1006/obhd.1999.2870, available online at http://www.idealibrary.com on
Incomplete Information, Inferences, and
Individual Differences: The Case of
Environmental Judgments
David H. Ebenbach and Colleen F. Moore
University of Wisconsin–Madison
A model for inference of missing information is explicated and
testedintwostudies(Ns ؍ 74, 76) of judgments abouttwoenviron-
mental issues (endangered species reintroduction and the siting
of a waste processing facility). Participants made judgments of
scenarios in which information relevant to the judgment was
varied orthogonally and, in some cases, relevantinformation was
missing. The results showed individual differences—as well as
intraindividual differences—in the assumptions participants
made about missing information and in the tendency to infer
missing cues. Reported assumptions about missing information
predicted some aspects of the judgments. The data for only a
small minority (15%) of the participants were consistent with the
inferred values model. Participants may use different methods
for dealing with missing information at different times or may
not generally follow either an inference or averaging model in
such contexts. Less favorable judgments were given for scenarios
with incomplete information (the “penalty” effect), and this effect
showed individual and intraindividual variation thatwas related
to reported assumptions about missing information. We discuss
the implications of these results for societal conflicts over contro-
versial issues and for understanding the sources of individual
differences in judgments.
᭧ 2000 Academic Press
Vice President Al Gore (1992), in his influential book Earth in the Balance,
notes that “We must acknowledge that we never have complete information.
The authors thank Jessica Gershaw, Shawnee Parsil, Jenny Kling, Joseph Corr, and Scott
Caldwell for their invaluable help at every stage of this project. David H. Ebenbach is now at
Bryn Mawr College, Philadelphia, Pennsylvania.
Address correspondence and reprint requests to Colleen F. Moore, Department of Psychology,
University of Wisconsin, 1202 West Johnson Street, Madison, WI 53706. E-mail: cfmoore@
facstaff.wisc.edu.
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Copyright ᭧ 2000 by Academic Press
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