A theoretical model is proposed for confidence in knowledge based on the assumption that people are good judges of the reliability of their knowledge, provided that the knowledge is representatively sampled from a specified reference class as defined by E. Brunswik (1943). Experiments with 177 college students support the theory. (SLD)

This article gives a comprehensive description of a theory for efficient assessment of knowledge. The essential concept is that the knowledge state of a subject, with regard to a specified field of information, can be represented by a particular subset of problems that the subject is capable of solving. (SLD)