Covariates have been used in mixture IRT models to help explain why examinees are classed into different latent classes. Previous research has considered manifest variables as covariates in a mixture Rasch analysis for prediction of group membership. Latent covariates, however, are more likely to have higher correlations with the latent class…

This article focuses on analysing the effect of educational differentiation policies of OECD educational systems on socioeconomically disadvantaged students, based on data from PISA 2009. The analysis is conducted on the basis of a definition of two subgroups of disadvantaged students: those that achieve high scores, and those obtaining scores…

This paper seeks to explore the extent of definite article usage variation in several varieties of English based on a classification of its usage types. An annotation scheme based on Hawkins and Prince was developed for this purpose. Using matching corpus data representing Inner Circle varieties and Outer Circle varieties, analysis was made on…