This is an open access article under the CC-BY-SA license. REiD (Research and Evaluation in Education), 6(1), 2020, 51-65 Available online at: http://journal.uny.ac.id/index.php/reid Item parameters of Yureka Education Center (YEC) English Proficiency Online Test (EPOT) instrument 1 Endrati Jati Siwi; *1 Rosyita Anindyarini; 1 Sabiqun Nahar 1 Yureka Education Center Yogyakarta Jl. Palem Hijau No. 120, Sidoarum, Godean, Sleman, Yogyakarta 55264, Indonesia * Corresponding Author. E-mail: anin@eurekatour.com Submitted: 1 April 2020 | Revised: 29 April 2020 | Accepted: 15 May 2020 Abstract Yureka Education Center (YEC) is one of the institutions which has developed an online-based English proficiency test. The test is called the English Proficiency Online Test (EPOT) which follows the TOEFL ITP (Institutional Testing Program) framework. Thus, this study aimed to analyze the characteristics of EPOT instruments consisting of Listening, Structure, and Reading subtests, which later the quality of each EPOT test item is identified. This study used a descriptive quantitative approach by describing the characteristics of EPOT test items in terms of item difficulty index, item discrimination index, test information’s function, and test measurement’s errors. The data were collected through EPOT trials conducted by 2,652 online test-takers as participants from 20 provinces in Indonesia. The collected data were then analyzed using the Item Response Theory (IRT) approach using the BILOG program on all logistic parameter models which began with the item compatibility test against the model. Based on the results of the analysis, all subtests match the 3-PL model. Most of EPOT’s test items had a good range of difficulty index and discrimination index. The EPOT information’s function shows that accurate items are used on the 3-PL model for a certain capability range. This study is expected to point out that the EPOT test could be used as an alternative English proficiency test that is easy to use and useful. Keywords: analysis, parameter, EPOT, listening, structure, reading How to cite: Siwi, E., Anindyarini, R., & Nahar, S. (2020). Item parameters of Yureka Education Center (YEC) English Proficiency Online Test (EPOT) instrument. REiD (Research and Evaluation in Education), 6(1), 51-65. doi:https://doi.org/10.21831/reid.v6i1.31013. Introduction In this era of globalization or better known as free trade, each individual is re- quired to prepare reliable skills, especially in the communication field. In the current situ- ation, English has a big role related to global communication between countries. Therefore, each individual is expected to be able to mas- ter English actively both oral and written. As in Indonesia, English is one of the foreign languages learned at school. Nowadays, for- eign languages, especially English, have an important role, especially in careers. The working world will give high appreciation to the people who have good English ability (Handayani, 2016, p. 106). English ability is needed for various job positions, such as teachers, employees, receptionists, security guards, programmers, and job seekers. Many companies, government agencies, including the selection process for civil servant candi- dates (Calon Pegawai Negeri Sipil or CPNS) require English proficiency, one of which is proved by a Test of English as a Foreign Language (TOEFL) certificate (Arnani, 2019). In addition to functioning as a require- ment for studying abroad and applying for work, the usage of TOEFL in Indonesia has