Regardless of the discipline in which you’re writing, you must support any claims you make with evidence—facts, statistics, examples and illustrations, expert opinion, and so on.
The kinds of evidence used in different disciplines commonly overlap. Students of geography, media studies, and political science, for example, all might use census data to explore different topics. The evidence that one discipline values, however, might not be sufficient to support an interpretation or a conclusion in another field. For example, psychologists, who look for evidence in case studies and in the results of experiments, seldom use expert opinion as evidence.
Evidence typically used in various disciplines