DOI link for Psychometric Models
Psychometric Models book
The previous chapter discussed the properties that observations should have in order to be considered measurements, according to different conceptions of what measurement is. Although such theories are important, in psychometric practice they play a background role. In the foreground, psychometric practice is guided by a more statistical approach to test scores. That is, psychometrics generally starts off from the interpretation of the observations as data, for which an adequate statistical model should be found. This approach gave birth to the major psychometric models currently used: the classical test theory model, the modern test theory model, and the generalizability model. Each of these approaches could be described as data-oriented, in the sense that their main use lies in the analysis of empirical data (rather than, say, in characterizing tests theoretically or in proving properties of measurement structures). As such, they are heavily informed by practical concerns.