Self-report inventories assessing personality or psychology are classic examples of such measure. Inventories are questionnaires with many items. Most typical Performance Tests measure traits . Traits are intercorrelated clusters of thoughts, feelings, and behavior presumed to remain relatively stable across time and situations. Traits are usually construed as dimensions, continuous attributes which can be used to rate or rank individuals.
Traits are continuous and everyone can be ranked somewhere on the continuum.
A collection of traits are how personality is typically characterized. Walter Mischel and other have questioned whether traits are largely an illusion. His argument focused on the lack of stability in behavior across time and situations. The truth is that people are not as consistent as we may think. Mischel notes that people may erroneously assume traits are real because we tend to see most people in a limited range of situations, hence we attribute the consistency in their behavior to them, never realizing how much they vary in different contexts.