This paper presents an overview of the theoretical, methodological, and applied contributions that the author's research program on prediction of performance has made to the literature on judgement and decision. It is shown that the rules people employ to combine information about motivation and ability in prediction of performance depend upon nature and difficulty of task as well as age, culture, and role of the judges. Also, subjects have separate initial opinions for cognitively distinct units, and they make imputations about unavailable information. Results from studies of school teachers and managers further disclosed that decision tasks have high construct validity and so they may be useful for selection and training purposes. New directions, for further research in judgment and decision are also discussed.