can you add parameters to a model of learner behavior in r? what is an irt model what is the irt model used for learning irt model definition what are intert models used for how to use irt model in glm which is a good way to fit an irt model? how can i use irt model is irt a learning model why is itrt model useful what is the role of imt in learning what is irt model can i use irt models what is irt model what is an irt model of learning why use irt model is itr model used in glm how to use irt model what kind of model is irist what is an irt model used for