Difficulties in managing students' hypotheses in the context of the scientific inquiry process in the science classroom (Marlot & Morge, 2016) are mainly expressed during the negotiation phases (Margolinas, 2004). The aim of this research is to uncover possible changes in the practical epistemology (PE) of novice teachers during simulation-based training (SBT). This doctoral research Project, carried out under French-Swiss co-supervision, is based on a training course for novice teachers (NT) aimed at acquiring skills related to managing students' hypotheses, in elementary school, on the subject of blood circulation. The responses of a NT before and after the SBT were compared on the basis of four indicators: facets of knowledge (Tiberghien et al., 2008), focus of the initial question (Orange, 2012), epistemic tasks (Malkoun & Tiberghien, 2008) and the six cognitive process dimension (Anderson & Krathwohl, 2014). The results allowed us to see a trend of evolution in the indicators. Based on some of the EP elements discovered in this study, we make some conjectures about the system of representation of science teaching to this NT.