One of the core assumptions of knowledge space theory (KST) is that the answer of a
subject to an item can be dichotomously classified as correct or incorrect. Schrepp (1997)
provided a very first attempt to generalize the main KST concepts to items with more than
two response alternatives, but his work has not had a strong impact on the subsequent
research on KST. The aim of the present article is to introduce a new formulation of the
polytomous KST, starting from the work of Schrepp and broadening it to a wider extent …