chapter  1
10 Pages

: What is generalizability theory?

Generalizability theory: Origin and developments Not all measuring procedures can be perfectly accurate. In the social and health sciences in particular, but in the natural sciences as well, we can rarely assume our measurements to be absolutely precise. Whether we are attempting to evaluate attitudes to mathematics, managerial aptitude, perception of pain, or blood pressure, our scores and ratings will be subject to measurement error. This is because the traits or conditions that we are trying to estimate are often difcult to dene in any absolute sense, and usually cannot be directly observed. So we create instruments that we assume will elicit evidence of the traits or conditions in question. But numerous in¢uences impact on this process of measurement and produce variability that ultimately introduces errors in the results. We need to study this phenomenon if we are to be in a position to quantify and control it, and in this way to assure maximum measurement precision.