Decision Making "Biases" and Support for Assumption-Based Higher-Order
  Reasoning
  Unaided human decision making appears to systematically violate consistency
constraints imposed by normative theories; these biases in turn appear to
justify the application of formal decision-analytic models. It is argued that
both claims are wrong. In particular, we will argue that the "confirmation
bias" is premised on an overly narrow view of how conflicting evidence is and
ought to be handled. Effective decision aiding should focus on supporting the
contral processes by means of which knowledge is extended into novel situations
and in which assumptions are adopted, utilized, and revised. The Non- Monotonic
Probabilist represents initial work toward such an aid.
