Abstract: Rasch model is a latent trait model which has drawn international interest among researchers. It provides a promising solution to ensure the objective measurement in psychological science. However, the research and applicatoin of Rasch model are not as popular as expected among domestic scholars. Unlike general IRTs that adopt a “the model fits data” position and use different parameters to accommodate the idiosyncrasies of the data set, the Rasch model requires that “data fit the model”. Its unique features including the same metric shared by persons and items, data linearity, and parameter separation ensure the achievement of objective measurement. The foci of future development of Rasch model include multidimensional Rasch model, test equating and linking, computer adaptive testing, and Rasch-based measurement system such as Lexile framework

Key words: Rasch model, latent trait model, objective measurement