The Development of a Measurement Instrument to Assess Student’s Competence in Connecting the Multiple Representations in Chemistry on Acid-Base Titration

The purpose of this research was to develop a measurement instrument to assess student’s competence in connecting multiple representations in chemistry, specifically focusing on acid-base titration topics. The student’s competency was categorized into three levels, ranging from Level 1, where students demonstrate a correct understanding of the concept of acid-base titration at the macroscopic, submicroscopic, and symbolic levels without connecting these levels, to Level 3, which indicates a complete and correct understanding of the concept and the ability to connect its relationships across all three levels of representation. The instrument comprised 11 items based on the defined competencies. Data were collected from 344 students in grades 11 and 12 at the high school level. The instrument was analyzed for reliability and validity using Rasch analysis. Results indicated that the standardized residual responses for the developed items met the criteria for local independence as defined by the Rasch model. When comparing the difficulties of items and students' abilities on the same scale, the discrimination of items and the reliability of items met the criteria. However, the Rasch analysis suggested the need for revisions of some questions in the instrument for further study. The measurement instrument could serve as a standardized test for assessing students' competence in connecting multiple representations in chemistry, specifically within the context of acid-base titration topics.