Sunday

10/05/2020

Measurement of change presents a nasty challenge. We expect persons (patients, students, experimental subjects) to change from Time 1 to Time 2. But the functioning of test items ... may also change, even when identical data collection protocols are used. The challenge is to measure persons and items in the same clearly defined frame of reference encompassing both time points, so that measurements of change will have unambiguous numerical representation and substantive meaning