What are the important issues?
Response Rate:
50% to 90% is preferablebut this may be unrealistic. Telephone, mail and computer methods may result in much lower response rates.

Sample Types:
Haphazard - Chosen by hit and miss methods, for example, man on the street. Risk: Can be wildly off! Watch Leno and Letterman for the Man in the Street!

Purposive Sample - A deliberately chosen nonrandom group with some specific purpose. You'd better hope that the small group is on target. For example, asking college presidents about the best small college may not be the same as asking students. When was the last time these old coots were in a college dorm?