The effects of thought experiments about mechanics on attitude, conceptual understanding and argumantation skills

The aim of study is to search the effect of pre-service science teachers' attitude on physics and physics laboratory lessons, their ability to create argumentation, their conceptval understanding about mechanics. The study is conducted with pre-service science teachers who are in their first year studying in science education department in 9 Eylül University in 2019-2020 academic year in fall semester. Sample was divided into experimental and control groupwith random selection by determining two groups from first year classes which have near academic success rate. It's requested from pre-service science teachers' to hypothesize abouth given thought experiment first with their imagination and after that they asked to explain the reasons, by handing out developped worksheets which start with thought experiment. In this process, teachers' who are mentioned above, are asked to create argumentation by reinterpreting the hypothesis of previous thought experiments data with the real experiment data. In this process, pre- service science teachers' are asked to create an argument model by reinterpreting the thought experiment hypothesis data with real experimant data. Meanwhile in the control group, the thought experiment part of the study sheet develophed for the experimental group was removed. To explain the same mechanistic concept to the pre-service teachers, data were collected by establishing a normal experimental setup and they were asked to interpet this data and create an argument model. The argument generation models of the pre-service teachers in all groups in the process were evaluated according to the scale developed by Cho and Jonassen (2002) to determine the quality of the discussion, and the data were the digitized and transferred to the computer environment. In the research, 'Physics Attitude Scale', 'Attitude Scale Towards Physics Laboratory', 'Mechanical Open Ended Conceptual Understanding Form' were applied to pre-test and post-test, and the experimental and control groups were compared. The content analysis was carried out by interviewing 3 people (successful 1, medium 1, weak 1) selected according to the scores of the pre-service teachers from the mechanical open –ended conceptual understanding questions, and getting their opinions on the worksheets used in the process. According to the results obtained in the study, when the answers given by the pre-service science teachers to the MAUKAF were analyzed, it was observed that there was no difference between the post-test scores of the pre-service teachers in the experimental group compared to the post-test scores of the pre-service teachers in the control group. When the pre-service teachers' ability to create an argument model was examined, a significant diffirence was found between the experimental and control groups. According to this diffirence, it was stated that the worksheets enriched with the thought experiment conributed to the pre-service science teachers ability to create arguments in the process. There was no significant difference between the attitudes of pre-service teachers in the experimental and control groups towards physics and physics laboratory courses.The results obtained were compered with similar studies in the literature and suggestions for future studies were preented. Keywords: Thought experiment, argument, conceptual understanding, mechanic.