An Evaluation of the Two Parameter (2-PL) IRT Models Through a Simulation Study


OLMUŞ H., Nazman E. , Erbas S.

GAZI UNIVERSITY JOURNAL OF SCIENCE, vol.30, no.1, pp.235-249, 2017 (Journal Indexed in ESCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 30 Issue: 1
  • Publication Date: 2017
  • Title of Journal : GAZI UNIVERSITY JOURNAL OF SCIENCE
  • Page Numbers: pp.235-249

Abstract

The aim of the study is to evaluate parameter estimation of two-parameter item response theory (2-PL IRT model) using Joint Maximum Likelihood (JML) estimation technique. Hence, a simulation study is conducted in terms of various sample sizes, item numbers and ability parameter levels for low and high discirimination parameter levels. Hereby, the examinee ability parameter, item discrimination parameter and difficulty parameter are obtained as well as Test Information Function (TIF) and point-biserial correlation. One of the highlighted results indicates that the level of discrimination parameter plays an important role in parameter estimation for 2PL IRT models.