Concept analysis and instrument feasibility analysis of students' critical thinking test instrument based on multiple representations of stoichiometry

The provision of valid and appropriate questions to be used as an evaluation tool in the learning process must always be strived for. Instruments in schools today are still lacking in measuring students' critical thinking. This study tested a stoichiometry test instrument which was developed to measure students' critical thinking. The test instrument consisted of 25 reasoned multiple-choice questions and was developed based on the revised version of Bloom's Taxonomy. The research method was carried out using quantitative methods consisting of four stages, namely concept analysis based in accordance with Indonesia's competency-based 2013 curriculum, assessment of content validity based on expert judgment, empirical assessment of construct validity based on unidimensional testing, and assessment of reliability based on Rasch modeling. The content validity assessment obtained an Aiken Index of 0.81 with a high category. On the other hand, the construct validity assessment using unidimensional test obtained an eigen value of the initial component of 6.34 which was bigger than the other components, and the reliability assessment obtained a Cronbach's Alpha score of 0.75. From the outcome of this research, an evaluation instrument on reasoned multiple-choice questions of students' critical thinking that is valid and feasible to use and is ready to be tested in a limit sample for the quality of empirical implementation has been produced.