%J Proceeding of International Conference On Research, Implementation And Education Of Mathematics And Sciences 2014 %L UNY11485 %I Yogyakarta State University %A Supahar Supahar %T THE ESTIMATION OF INQUIRY PERFORMANCE TEST ITEMS OF HIGH SCHOOL PHYSICS SUBJECT WITH QUEST PROGRAM %D 2014 %X This paper is aimed to determine the results of the parameter estimation of inquiry performance test item of high school physics subjects with polytomous pattern using the QUEST program. The estimation of the item test based on the item response theory (IRT) by applying the model of Partial Credit Model (PCM ) on the student's response of inquiry performance test. The estimation included fit model the PCM, and the estimation of test items difficulties level. Based on the estimation of test items parameters on the IRT according to the model of PCM known that the items of inquiry performance test have an INFIT scale of MNSQ between 0.77 to 1.30 thus meet the fit criteria with PCM models, and test item difficulties fulfilling the criteria of a good test item because of the test item difficulties in the range of -2 < b < +2. %K parameters of the test item , Partial credit model (PCM) , inquiry performance, high school physics subjects