1 The confidence with which the conclusions of an empirical investigation can be generalized to naturally occurring situations in which the phenomenon under investigation occurs. See also validity, validity generalization. Compare external validity, internal validity.
2 In the writings of the Hungarian-born US psychologist Egon Brunswik (1903–55) and his followers, the correlation between a sensory cue (2) that an organism uses to judge an ecological criterion and the actual though imperceptible ecological criterion itself. See also Brunswikian, ecology (2), lens model, probabilistic functionalism.