A note on simple gain score precision

A distinction is necessary between two concepts of measurement precision. R eliability is population dependent and information is examinee dependent. B oth concepts also apply to the simple gain score. Low reliability implies t hat it is not appropriate to correlate the gain score with variables in a p opulation, and low information implies that no precise statements can be ma de about an examinee's true gain. However, low reliability does not imply t hat statements about within-examinee change are necessarily imprecise.