The Probability Inquiry Environment (PIE) is being designed as a computer-mediated collaborative inquiry environment to aid middle school students in learning elementary probability. This paper reports on a study in which seventh grade students engaged in probabilistic reasoning while interacting with a preliminary version of PIE. By analyzing the reasoning used by students, it was found that the findings from the standard "misconceptions" literature do not do justice to the wide range of viewpoints voiced by the students. In particular, the students did not consistently invoke such well-documented misconceptions as representativeness and the law of small numbers. Instead, the students invoked a great variety of intuitions, some of which approach normative reasoning in probability, and others which interfere with normative reasoning. The paper then discusses how probability instruction can be improved by introducing students to a progression of inquiry activities that build from the students' existing intuitions. Contains 28 references. (Author/JRH)