Briefly stated, the findings are that when presented with an array of
data or a sequence of events in which they are instructed to discover
an underlying order, subjects show strong tendencies to perceive order
and causality in random arrays, to perceive a pattern or correlation
which seems a priori intuitively correct even when the actual correlation
in the data is counterintuitive, to jump to conclusions about the correct
hypothesis, to seek and to use only positive or confirmatory evidence, to
construe evidence liberally as confirmatory, to fail to generate or to
assess alternative hypotheses, and having thus managed to expose themselves
only to confirmatory instances, to be fallaciously confident of the validity
of their judgments (Jahoda, 1969; Einhorn and Hogarth, 1978). In the
analyzing of past events, these tendencies are exacerbated by failure to
appreciate the pitfalls of post hoc analyses.
                -- A. Benjamin