摘要:Engineering design process-oriented STEM activities are activities that involve solving a real-world problem with teamwork by using integrative engineering design and engineering applications using scientific and mathematical concepts and 21st century skills. The research aimed to examine the effects of engineering design process-oriented STEM activities, which were developed for sound concept, on the conceptual development of 6th grade students. In the research, comparative case study design was used. The study group consisted of 40 students attending a middle school in Kayseri, Turkey. The teaching was carried out by the activities in science curriculum in the control group, while it was carried out by engineering design process-oriented STEM activities in the experimental group. Each student was individually interviewed using 11 open-ended questions in a verbal format. The mean of Kappa coefficients of the questions was 0.93. As a result of content analysis, 11 categories, including 21 themes and 81 codes, were obtained. When the differences between pre- and post-interviews were examined, it was seen that conceptual understanding levels of the students in experimental group were more positive than the students in control group. This shows that engineering design process-oriented integrated STEM activities have positive effects on students’ conceptual understanding of sound.