Equating Test Instruments Using Anchor to Map Student Abilities Through the R Program Analysis

This study aims at investigating the equivalence of mathematics try out scores junior high school through anchor. In study, 2 Parameters Logistic (2PL) model Item Response Theory (IRT) analysis was used Haebara method. The estimation step equating parameter utilized equateIRT package in R program. results show that relationship between questions 1 and cannot be said to equivalent. After analyzing calculating regression equation, it can concluded Mathematics National Examination (MNE) has a higher level difficulty than 1. Equating 2* method for PL will provide equal or fair test takers who work on 2. samples were taken from MNE distributed Makassar 2014 which consisted question packages. Question responded by 2099 students, while 2068 students. design common item design. With made, future, takers’ ability detected properly if they similar tests, even though packages are relatively different.