A.C. Pratama, Supahar, Warsono, Jumadi
Problem solving is one of the focuses in physics education research. To solve the problem in physics, students often apply the vector representation to facilitate in understanding problems before they use mathematics representation. To measure both representations well requires a good assessment, so in this research we aims to: 1) develop an instrument test to measure the vector and mathematics representation ability of high school students, 2) determine the characteristics of the instrument test items. The research method used was the combination of 4D and ADDIE model. The test instrument developed was an essay test consisting of 15 items. These items had been validated by instrument experts, practitioners and peers. The sample is determined by purposive sampling which consisting 285 high school students in Samarinda. The polytomous data were analyzed according to the partial credit model (PCM). Research results show that 13 items of the test fit to PCM with the test reliability 0.83 and the items' difficulty indexes ranged from -1.11 to 1.58. Based on the information function and SEM, this test is suitable for students that whose ability -1.40 to over 3.00. Therefore, the test instrument is valid and reliable to measure the vector and mathematics representation ability. © 2018 Published under licence by IOP Publishing Ltd.
Department of Physics Education, Yogyakarta State University, Indonesia
