The answer is the central idea
The type of research carried out by the professor at the University of Arizona is called Primary Research while the research which references that is called Secondary Research.
<h3>What is Primary Research?</h3>
This refers to research wherein data is collected directly from the sample as opposed to secondary research which dwells on primary research that has already been carried out by others.
See the link below for more about Primary and Secondary Research:
brainly.com/question/13672588
