Most of the time, the relationship between terms in different concept categories is narrowing. The secondary concepts help to narrow or modify the broad primary concept to a topic specific enough and small enough to fit the required size of your project.
Thesis statement:
In the topic statement above, the secondary concept "American" narrows or modifies the focus of the primary concept "colonists".
There are two ways to express the "narrowing" or "modifying" relationship in the search statement syntax. These are: