This study aims to understand and explain how the pre-service elementary teachers manage the experimentation process. This study is important in terms of finding out why teachers do not prefer experimental methods and how these thoughts can be substituted with positive thoughts. This study employed the mixed-method design (combines quantitative and qualitative research techniques into a single study) based on grounded theory. The qualitative approach is dominant in the study in which the quantitative research series is grounded in the case study, which is a qualitative pattern. The number of participants varied at different stages of the research according to the variety of assessment tools used in the research. In the study data collection process is; determining the purpose of the research, implementation of the self-efficacy scale (pre-test/post-test), examination of experiment reports at the end of the first semester, determination of student opinions about the experimental studies at the end of the second semester, implementation of focus group interviews, and reporting the results. According to the findings, laboratory practices were effective in increasing participants' self-efficacy beliefs. It has been determined that pre-service teachers experienced difficulties in experiment knowledge, material knowledge, lack of theoretical knowledge and not doing experiments before, experiment planning, implementation, evaluation and reporting processes. The experimental reports revealed that pre-service teachers did not manage the application process well, did not observe carefully, attentively and regularly, could not use standard measurement tools and units, did not record the measurements regularly, and could not present their data in an appropriate and effective manner. Participants emphasised on learning by doing and experiencing definitions than other codes. The emphasis on learning by doing and experiencing is observed in the descriptions since scientific truth is reached through experimenting in the laboratory courses. The positive experiences that pre-service teachers will gain by conducting experiments on their own in the faculties of education will make the most important contribution to their self-efficacy beliefs. The fact that teachers who have high self-efficacy beliefs and experience in doing experiments perform experiments in science lessons will provide students with considerable acquisitions. Early science education is very important for students to acquire scientific process skills in the short term, to learn to think like a scientist, and to prefer to study science-related fields in the long term.

Experiment-related perceived self-efficacy, scientific process skills, pre-service teachers.