Confirmation Bias

Definition: Confirmation bias is a theory which describes the psychological inclination to see evidence which supports our theory, and to ignore or avoid evidence which contradicts it.

Application: Confirmation bias is often an issue in police investigations, in which officers will (unconsciously) selectively see evidence that supports their pre-conceived theory of a case, and not see evidence which contradicts their theory.

Adaptation: Confirmation bias is a significant issue when conducting research or evaluation in a community development capacity. For instance, if we have a strong emotional investment in a community development organization, our evaluation of the program may unintentionally avoid any evidence that the program is not effective in achieving its outcomes. Because of this tendency, it is important for evaluators and researchers to acknowledge their biases and consider their impact on the evaluation results.

References:

Fischhoff, B. and Beyth-Marom, R. (1983). Hypothesis evaluation from a Bayesian perspective. Psychological Review, 90, 239-260.