A preliminary study is reported of the use of new multifaceted Rasch measurement mechanisms for investigating rater characteristics in language testing. Ratings from four judges of scripts from 50 candidates taking the International English Language Testing System test, a test of English for Academic Purposes, are analyzed. The analysis illustrates how multifaceted Rasch measurement can be used to examine inter-rater consistency, differences in rater harshness, available grades on the rating scale, and the effect that between-rater variation has on the measurement of individual candidates. Although the main focus of the paper is on modeling and estimating rater variation, Rasch modeling also has the potential for practical applications controlling the effects of the variation it describes. One such application is considered: the use of the model to explore the relationship between varying amounts of multiple marking and the resulting ability estimates of candidates, to see if it may be possible to reduce the amount of multiple marking required to produce stable and reliable estimates of ability. Contains 18 references. (LB)