Page 289 - Mechanical Engineers' Handbook (Volume 2)

280 Analysis, Design, and Information Processing

dental base rate. When information updates occur, this individuating information
is often given much more weight than it deserves. It is much easier for the impact
of individuating information to override incidental base rates than causal base rates.
4. Conservatism. The failure to revise estimates as much as they should be revised,
based on receipt of new significant information, is known as conservatism. This is
related to data saturation and regression effects biases.
5. Data Presentation Context. The impact of summarized data, for example, may be
much greater than that of the same data presented in detailed, nonsummarized form.
Also, different scales may be used to change the impact of the same data consid-
erably.
6. Data Saturation. People often reach premature conclusions on the basis of too small
a sample of information while ignoring the rest of the data, which is received later,
or stopping acquisition of data prematurely.
7. Desire for Self-Fulfilling Prophecies. The decision-maker values a certain outcome,
interpretation, or conclusion and acquires and analyzes only information that sup-
ports this conclusion. This is another form of selective perception.
8. Ease of Recall. Data that can easily be recalled or assessed will affect perception
of the likelihood of similar events reoccurring. People typically weigh easily re-
called data more in decision making than those data that cannot easily be recalled.
9. Expectations. People often remember and attach higher validity to information that
confirms their previously held beliefs and expectations than they do to disconfirming
information. Thus, the presence of large amounts of information makes it easier for
one to selectively ignore disconfirming information such as to reach any conclusion
and thereby prove anything that one desires to prove.
10. Fact–Value Confusion. Strongly held values may often be regarded and presented
as facts. That type of information is sought that confirms or lends credibility to
one’s views and values. Information that contradicts one’s views or values is ig-
nored. This is related to wishful thinking in that both are forms of selective per-
ception.
11. Fundamental Attribution Error (success/failure error). The decision-maker associ-
ates success with personal inherent ability and associates failure with poor luck in
chance events. This is related to availability and representativeness.
12. Habit. Familiarity with a particular rule for solving a problem may result in reuse
of the same procedure and selection of the same alternative when confronted with
a similar type of problem and similar information. We choose an alternative because
it has previously been acceptable for a perceived similar purpose or because of
superstition.
13. Hindsight. People are often unable to think objectively if they receive information
that an outcome has occurred and they are told to ignore this information. With
hindsight, outcomes that have occurred seem to have been inevitable. We see re-
lationships much more easily in hindsight than in foresight and find it easy to change
our predictions after the fact to correspond to what we know has occurred.
14. Illusion of Control. A good outcome in a chance situation may well have resulted
from a poor decision. The decision-maker may assume an unreasonable feeling of
control over events.
15. Illusion of Correlation. This is a mistaken belief that two events covary when they
do not covary.