The article reports on the careful examination of the interactions in students aged 13 and 14 years old when dealing with a teaching sequence about randomness and certainty. We use photographic images as the material medium that enabled us to identify students' conceptions of randomness in the "paramathematician" status; that is to say, the notions functions as tools to predict events. We rely on the notion of a didactic contract, didactic means, and the returning of the theory of didactic situations to design situations, implement them and, then, analyze the students' productions. The research methodology adopted was the qualitative analysis in ongoing phases, such as analysis a priori, experimentation, and analysis of results. Through this research arises, among other things that most students assigned to the random phenomena, subjective meanings stating clearly that they did not accomplish to identify the random event referred to in their own stories.