Even though experimental design (ED) in open inquiry is important for more authentic scientific inquiry, it is not easy for students. The objective of this research was to identify factors considered important in students' ED and explore how to utilize it to improve students’ ED. To achieve the objective, in the first step, eighteen middle-school students in a gifted center participated in this study voluntarily. They were asked to design experimental procedures without any guidelines or help. Students’ EDs were analyzed qualitatively to extract difficulties that students experienced when designing experimental procedures. Based on analysis results, 17 factors were identified as factors to be considered for students’ ED and structured in a form of checklist. In the second step, the checklist was provided to 50 students in the gifted center as guidelines for their ED. They were then asked to design experimental procedures. Comparing scores of these students’ ED with those of the control group, it was found that these factors were significantly effective for improving students’ ED with high effect size. In conclusion, results of this research suggest that effective teaching strategy for students’ ED in scientific open inquiry can be obtained based on analysis about their difficulties in ED.
Keywords: checklist, experimental design, gifted education, scientific open inquiry.