Latent Trait Models

A latent trait model is a measurement model that describes the relationship between the probability of a particular score on an item (e.g., correct/incorrect, rating on an ordered scale) and the latent variable or the latent trait that explains this score. For an individual responding to a particular item, this probability depends on his or her latent trait value and properties of the item, such as its difficulty and its discrimination power. The term latent trait model, a synonym of item response model, is not in as much use today.