A Short Note on Obtaining Point Estimates of the IRT Ability Parameter with MCMC Estimation in Mplus: How Many Plausible Values Are Needed?

Autor/inn/en	Luo, Yong; Dimitrov, Dimiter M.
Titel	A Short Note on Obtaining Point Estimates of the IRT Ability Parameter with MCMC Estimation in Mplus: How Many Plausible Values Are Needed?
Quelle	In: Educational and Psychological Measurement, 79 (2019) 2, S.272-287 (16 Seiten)Infoseite zur Zeitschrift PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0013-1644
DOI	10.1177/0013164418777569
Schlagwörter	Item Response Theory; Monte Carlo Methods; Markov Processes; Outcome Measures; Scores; Correlation; College Entrance Examinations; Bayesian Statistics; Models; Statistical Bias; Computer Software; Test Items; Foreign Countries; Saudi Arabia + Suchen Sie Ihr Suchwort? Item-Response-Theorie; Monte-Carlo-Methode; Markowscher Prozess; Korrelation; Aufnahmeprüfung; Analogiemodell; Test content; Testaufgabe; Ausland; Saudi-Arabien
Abstract	Plausible values can be used to either estimate population-level statistics or compute point estimates of latent variables. While it is well known that five plausible values are usually sufficient for accurate estimation of population-level statistics in large-scale surveys, the minimum number of plausible values needed to obtain accurate latent variable point estimates is unclear. This is especially relevant when an item response theory (IRT) model is estimated with MCMC (Markov chain Monte Carlo) methods in Mplus and point estimates of the IRT ability parameter are of interest, as Mplus only estimates the posterior distribution of each ability parameter. In order to obtain point estimates of the ability parameter, a number of plausible values can be drawn from the posterior distribution of each individual ability parameter and their mean (the posterior mean ability estimate) can be used as an individual ability point estimate. In this note, we conducted a simulation study to investigate how many plausible values were needed to obtain accurate posterior mean ability estimates. The results indicate that 20 is the minimum number of plausible values required to obtain point estimates of the IRT ability parameter that are comparable to marginal maximum likelihood estimation(MMLE)/expected a posteriori (EAP) estimates. A real dataset was used to demonstrate the comparison between MMLE/EAP point estimates and posterior mean ability estimates based on different number of plausible values. (As Provided).
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Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2020/1/01