ABSTRACT
The Rasch rating-scale model (RSM) is a member of the class of Rasch models (Rasch, 1961; Andersen, 1977; Andrich, 2005). Its application is particularly relevant when responses to items are in ordered categories. Table 5.1 shows three such formats, each in four categories. Also known as a Likert (1932), format it is an extension of the dichotomous response format and is used when more information may be obtained than from a dichotomous format. In elementary applications, the categories in the intended order are scored with successive integers, beginning with zero (0), and the scores of a person on multiple items of a test or questionnaire summed to characterize a person. In more-advanced applications, a probabilistic model, such as the RSM is applied. Examples of Ordered Category Assessments in a Rating-Scale Format
|
Strongly disagree |
Disagree |
Agree |
Strongly agree |
|
Never |
Sometimes |
Often |
Always |
|
Fail |
Pass |
Credit |
Distinction |
