Background Began after Tim Brewster was fired at the University of Minnesota. Now they have a new coach again! Wanted to try to predict next great coach. Proceeded to explore data available to answer this question. Data Data came from a few sources: http://www.cfbdatawarehouse.com/ Wikipedia Goals Predict the ‘ability’ of the coaches. Find other variables that explain variation in the ‘ability’ of the coaches.
Read More…
Validity for IRT Models Validity is important for any assessment and the argument should begin with psychometrics. How the psychometrics is performed directly impacts properties of the assessment that are assessed later for evidence of validity. Are scores reported below chance level? The validity of the psychometrics is particularly important for field test data. IRT Model Field Testing Field testing (FT) is essential to new assessment development or form building.
Read More…
Linking overview With item response theory (IRT), the ability scale is arbitrarily defined (commonly mean of 0 and sd of 1). Linking is useful to help place individual ability and IRT item parameters on the same scale. Particularly when two forms are administered to non-equivalent groups. Four linking methods are common: Mean/Mean Mean/Sigma Haebara Stocking Lord Linking Transformation Linking Designs Random Groups Single group with counterbalancing Common-item nonequivalent group design More details in Kolen & Brennan (2014).
Read More…