Misfits : people and their problems. What might it all mean?
Curtis, David D
Shannon Research Press
In the analysis of data, which arise from the administration of multiple choice tests or survey instruments and which are assumed to conform to a measurement model such as Rasch, it is normal practice to check item fit statistics in order to ensure that the items used in the instrument cohere to form a unidimensional trait measure. However, checking whether individuals also fit the measurement model appears to be less common. It is shown that poor person-fit compromises item parameter estimates and so it is argued that person-fit should be checked routinely in the calibration of instruments and in scoring individuals. Unfortunately, the meanings that can be ascribed to person-fit statistics for attitude instruments is not clear. A proposal for seeking the required clarity is developed. [Author abstract]
Item response theory, Data analysis, Measurement techniques
Curtis, David (2001) Misfits : people and their problems. What might it all mean? International Education Journal 2(4)