Place of thought experiments in physics problem solving: A qualitative investigations on first and fifth year physics teacher candidates

This is a case study made up of two steps, which respectively aimed at determining thought experiments developed by students in problem solving and determining structures of these thought experiments.The first step of this study was carried out with 22 first year and 28 fifth year students form the department of Teaching Physics. Six open-ended questions about the laws of motion were used as a measure and student?s answers, through coding, were analyzed in accordance with their ability to design a thought experiment. Participants for the second part were chosen by bearing in mind the characteristics of thought experiments. In addition to these, the average difficulty of the test was determined and through item analysis the questions asked in the test were found to be of intermediate level.As for the second step, in a non-participant observation, 5 first year and 4 fifth year students chosen in the first step were observed in another test consisting of four open-ended questions in order to determine their thought experiments. After the observation, the students were interviewed through a semi-structered protocol. The structures of the thought experiments that came out as a result of data analysis were compared and contrasted, and similarities and differences between first and fifth year students were discussed.