Premium
Limited‐information goodness‐of‐fit testing of item response theory models for sparse 2 P tables
Author(s) -
Cai Li.,
MaydeuOlivares Albert.,
Coffman Donna L.,
Thissen David.
Publication year - 2006
Publication title -
british journal of mathematical and statistical psychology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.157
H-Index - 51
eISSN - 2044-8317
pISSN - 0007-1102
DOI - 10.1348/000711005x66419
Subject(s) - goodness of fit , mathematics , statistics , null distribution , test statistic , contingency table , statistic , method of moments (probability theory) , null hypothesis
Bartholomew and Leung proposed a limited‐information goodness‐of‐fit test statistic ( Y ) for models fitted to sparse 2 P contingency tables. The null distribution of Y was approximated using a chi‐squared distribution by matching moments. The moments were derived under the assumption that the model parameters were known in advance and it was conjectured that the approximation would also be appropriate when the parameters were to be estimated. Using maximum likelihood estimation of the two‐parameter logistic item response theory model, we show that the effect of parameter estimation on the distribution of Y is too large to be ignored. Consequently, we derive the asymptotic moments of Y for maximum likelihood estimation. We show using a simulation study that when the null distribution of Y is approximated using moments that take into account the effect of estimation, Y becomes a very useful statistic to assess the overall goodness of fit of models fitted to sparse 2 P tables.