Abstract: In traditional paradigm of decision making research, participants make judgments or choice after playoffs and probabilities of each alternative are given. Previous studies indicated that people tend to overweight small probability when they face the problems with low probability in uncertain situation. However, this overweighting small probability phenomenon was challenged by a series of findings published recently using a new paradigm, called decisions from experience. In this paper two kinds of decisions, decisions from experience and decision from description, were introduced and differentiated from concept to methodology. D-E gap, a phenomenon showed people tend to underweight low probability event in decision-making experiments, and its different theoretical explanations were comprehensively reviewed. Finally, the implications of the study of decisions from experiences in the fields of learning and memory, human developmental, decision and judgment were discussed.

Key words: decisions from description, prospect theory, decisions from experience, D-E gap