The Rasch model is a psychometric model used in the social sciences to analyze categorical response data, usually collected using a content knowledge test or attitudinal questionnaire, in order to assess the extent to which a set of persons has a certain level of an attribute of interest (e.g., mathematical proficiency or level of anxiety) and the extent to which a positive answer to the questions or statements demands a certain level of that attribute (e.g., difficulty of a mathematical question or level of anxiety required in order to agree or endorse a statement). Originally developed in the 1950s by Danish mathematician Georg Rasch for the analysis of dichotomous responses to intelligence tests, the Rasch model in its most basic form states that the probability ...