The Indonesian adaptation of the control of variables strategy inventory

Control of variables strategy is one of the strategies involved in scientific discovery and verification of hypotheses. It is important to assess the development of scientific thinking of Indonesian students, but we cannot find any measurement to assess scientific thinking particularly control of variables strategy for Indonesian students. The purpose of this study was to conduct the Indonesian adaptation of the Control of Variables Strategy Inventory (CVSI). The CVSI is a paper and pencil instrument that measures three sub-skills of control of variables strategy: Identification, Interpretation, and Understanding. The procedures of adaptation included translating the CVSI from Germany to the Indonesian language, evaluating the content and conceptual equivalence, and designing the final form of the inventory. To obtain the psychometry properties, a sample of 162 eighth grade students completed the inventory. The hypothesized measurement model was unidimensional and was examined using confirmatory factor analysis. Fit model was obtained after conducting modification of model as shown by fit index Chi-square=6.596, df=5, p=.252, GFI=.986, CFI=.983, TLI=.966, RMSEA=.041. The model comprises five Interpretation items with the lowest loading factor. 44 and Cronbach’s alpha =. 610 as reliability coefficient. It seems that the items assessing Identification and Understanding skills that fit for 7, 8, and 9-grade students in Germany are not appropriate for eighth-grade students in Indonesia. Next research should examine whether this result is related to the development of the domain-general ability of reasoning, to domain-specific of physics knowledge, or to other factors.