Empirical data on student teachers' use and views of models in physics are investigated. Students’ explanations of phenomena are analysed with the link between model/theory and reality in focus. A secondary focus is how the students’ use of explanatory models is influenced by their views about the nature of scientific knowledge. The project has a combined cross sectional and longitudinal design. Written questionnaires are used, in combination with follow up interviews. Three different phenomena are discussed, a burning candle, a gas flame and a flask with air confined by a balloon. Data is analysed with respect to a theoretical model of learning assuming that students use several different explanatory models, and that they use more than one in explanations of everyday phenomena. Results from this exploratory study are planned to guide further research on how teaching can build upon different perspectives of models to improve student learning.