What are the differences between a Thurstone and Likert scale? Under what conditions is the one to be preferred above the other?

Everyone has traits and behaviors that form an individual attitude. “An attitude is a person's feeling toward and evaluation of some object or event. Attitudes have two important aspects: direction (positive/negative, for or against) and intensity (strength of feeling).” (Somer, Nd, para 1) If you like pizza, you have a positive attitude toward it. If you are a fanatic about pizza, then your positive feelings towards pizza are very intense. . .

This article addresses: The differences between a Thurstone and Likert scale? Under what conditions is the one to be preferred above the other?