A common approach when studying the quality of representation involves comparing the latent preferences of voters and legislators, commonly obtained by fitting an item-response theory (IRT) model to a
Global tests of DIF and global tests of fit in resulting Rasch models (RM) or graphical loglinear Rasch models (GLLRM) for each subscale and the total scale of 24 items across domains.
This worksheet allows you to see how IRT estimates the ML estimate of theta. Plus in the a and b for an item, as well as the response to each item (correct/incorrect).