In this paper, the structure of non-mathematicians' knowledge of probability is argued. Based on the analysis of the conceptual model (teachers' model) of probability, it is hypothesized that the mental model (non-mathematicians' model) of probability might consist of three different understandings (views), the case view, the frequency view, and the subjective view. In people's explanations of probabilistic statements about some concrete events, the hypothesized views are identified, and it is shown that an individual's explanations are often based on two or more views. The relationship between mental models and problem solving processes is discussed. It is demonstrated that the view that a problem solver took influenced problem solving processes. There are some cases where the frequency view has advantages in problem solving. The implication of multiple views of probability for mathematics education is also argued.
