Dr. Zelbing and her graduate assistant want to compile a list of personality traits using the approach advocated by Allport and Odbert. In order to do this, they get two copies of the unabridged dictionary of the English language, use it to look for words that are related to personality traits. When they are done several weeks later, they have a list of several thousand words that they will reduce based on duplicate terminology. Dr. Zelbing advocates for a(n) __________ to the study of personality.