Coverage and scope describe how much of a subject is discussed, or "covered" by the source. It is usually described in terms of breadth and depth. It goes from broad to narrow and from superficial to in-depth.
Here are some questions to ask yourself about the source:
Be sure the source has the kind of coverage of the topic that you want before you decide to use it.
Say you are looking for information about the Civil Rights Movement in the United States in the 1960s. Here are some possible sources:
Depending on your topic, assignment, or design brief, any of these sources might be of use to you. For instance, the Montgomery news item above is brief, but it contextualizes the importance of the event covered.