Polytomous models are for items that have more than two possible scores. The most common examples are Likert-type items (Rate on a scale of 1 to 5) and partial credit items (score on an Essay might be 0 to 5 points). IRT models typically assume that the item scores are integers.

What does Polytomous mean?

1 : divided into more than two secondary parts or branches — compare dichotomous. 2 : pinnatifid.

What is Polytomous variable?

A polytomous variable is a variable with more than two distinct categories, in contrast to a dichotomous variable. ... Other terms sometimes used for polytomous variables are polychotomous (just an extra syllable, also in contrast to dichotomous variables) and multinomial (in contrast to binomial).