Estimation of a four-parameter item response theory model

Eric Loken, Kelly L. Rulison

Research output: Contribution to journalArticlepeer-review

30 Scopus citations

Abstract

We explore the justification and formulation of a four-parameter item response theory model (4PM) and employ a Bayesian approach to recover successfully parameter estimates for items and respondents. For data generated using a 4PM item response model, overall fit is improved when using the 4PM rather than the 3PM or the 2PM. Furthermore, although estimated trait scores under the various models correlate almost perfectly, inferences at the high and low ends of the trait continuum are compromised, with poorer coverage of the confidence intervals when the wrong model is used. We also show in an empirical example that the 4PM can yield new insights into the properties of a widely used delinquency scale. We discuss the implications for building appropriate measurement models in education and psychology to model more accurately the underlying response process.

Original languageEnglish (US)
Pages (from-to)509-525
Number of pages17
JournalBritish Journal of Mathematical and Statistical Psychology
Volume63
Issue number3
DOIs
StatePublished - Nov 2010

All Science Journal Classification (ASJC) codes

  • Statistics and Probability
  • Arts and Humanities (miscellaneous)
  • Psychology(all)

Fingerprint Dive into the research topics of 'Estimation of a four-parameter item response theory model'. Together they form a unique fingerprint.

Cite this