Finding, Narrowing, Outlining Topics
http://www.io.com/~hcexres/textbook/narrowing.html

McMurrey, David A.
Illuminati Online
2001

Abstract:

In a technical-writing course, the ideal starting place is a workplace problem requiring some writing as part or all of the solution. With such a project, the audience and problem are there to help you narrow the topic. However, if you begin with a topic, it's harder to narrow. You are likely to end up with ten-pound textbook on automotive plastics, residential solar energy in the home, or La Niña. Narrow the topic and some careful research—the result will be a practical, useful document that doesn't go on forever. Narrowing means selecting a portion of a larger topic: for example, selecting a specific time period, event, place, people, type, component, use or application, cause or effect, and so on. Narrowing also means deciding on the amount of detail to use in discussing those topics.