Search for each concept as a separate set and then combine sets

Break your topic into individual concepts. Search for each concept separately and then combine the individual sets/concepts to retrieve information on your topic. Creating separate sets for each part of your topic allows you to modify your strategy and combine sets in different ways.

AND is used when you have two different concepts and you want to find articles that discuss both.

OR is used when you have similar terms and you want to find articles that include at least one of the terms.