How would I determine the variable level (nominal, ordinal, interval or ratio) for the following: Gary is a researcher interested in self-esteem. He develops an instrument he names the "I am great questionnaire." He administers the survey and collects information from 500 middle school learners. He calculates a self-esteem score for each child in the study and then groups the students as low, medium, or high self-esteem. Given this scenario please answer the following question.
Self-esteem, in Gary's study, is measured as a(n)___________ level variable.