Score equating based on small samples of examinees is often inaccurate for the examinee populations. We conducted a series of resampling studies to investigate the accuracy of five methods of equating in a common-item design. The methods were chained equipercentile equating of smoothed distributions, chained linear equating, chained mean equating,…

Any systematic approach to the assessment of students' ability implies the use of a model. The more explicit the model is, the more its users know about what they are doing and what the consequences are. The Rasch model is a strong model where measurement is a bonus of the model itself. It is based on four ideas: (1) separation of observable…