Index
An index is a set of multiple, related measures that are combined to better measure an abstract concept. In an evaluation survey, a number of similar questions could be asked to measure someone’s attitudes toward a program. For example:
Rate your agreement or disagreement with the following statements:
Overall, I enjoyed this program
This program improved my quality of life
I would recommend this program to a friend
I learned something new at this program
We could ask respondents to indicate their agreement to each statement on a scale from 1 to 5 (i.e., a Likert-type scale), then their responses would be combined to create an index.