eng Science and Education Publishing American Journal of Educational Research 2327-6150 2018-08-23 6 8 1198 1205 10.12691/education-6-8-20 EDUCATION20186820 article Vika Puji Cahyani vikapujicahyani@yahoo.co.id 1 Hari Sutrisno 1 2 Chemistry Education Masters and Doctoral Programs, Graduate School, Yogyakarta State University, Yogyakarta 55281, Indonesia This research aims to validate multiple representations instruments for measuring student's multiple representations skill of electrolytes and nonelectrolytes. This research uses quantitative descriptive method with nonexperimental approach. This research applies stratified sampling method with total 94 students who respond to 40 items multiple choices that cover macroscopic, microscopic, symbolic, and mathematical aspects. Rasch model in this research analyzes the instruments such as determining the unidimensionality, reliability, item map, item measure, item fit, and test information function. Data analysis shows that the finding of good category of validity and reliability of the instrument can be used as a diagnostic tool in the assessment of student's multiple representation abilities. http://pubs.sciepub.com/education/6/8/20/education-6-8-20.pdf descriptive quantitative multiple representation rasch model electrolyte and nonelectrolyte psychometric properties