In the frame hypothesis (CITATION), human concepts are equated with frames, which extend feature lists by a functional structure consisting of attributes and values. For example, a bachelor is represented by the attributes gender and marital status and their values ‘male’ and ‘unwed’. This paper makes the point that for many applications of concepts in cognition, including for concepts to be associated with lexemes in natural languages, the right structures to assume are not merely frames but stochastic frames in which attributes are associated with probability distributions over values. The paper introduces the idea of stochastic frames and suggests three applications: vagueness, ambiguity, and typicality.