Likert-type Ratings

Suppose that a self-esteem scale asks people to rate how much they agree or disagree with a series of items that ask about positive or negative personal qualities. Scoring instructions state that responses should be averaged across all items.

1. The Likert-type ratings for each item can have a score of 1, 2, 3, or 4. A distribution of scores is presented below.
   
   
2. Once the items are averaged, the overall mean self-esteem score can have values such as 1.00, 1.50, 1.75, 2.00, 2.50, 2.75, 3.25, 3.50, 3.75, 4.00. The distribution of the average across items is presented below.

Creating an average across multiple items that measure the same underlying construct (self-esteem) is thought to increase the reliability and validity of the scale. The numeric average of these items gives us a total score with a much wider range of possible values than just 1 to 4.