You are a researcher interested in measuring self-esteem. You give your participants a 10-item questionnaire with items, such as "I feel that I have a number of good qualities" or "I take a positive attitude toward myself." Participants indicate agreement to these questions on the same 5-point scales, ranging from 1 (not at all agree) to 5 (completely agree). On which scale level do you measure self-esteem?

Nominal

Ordinal

Interval

Ratio