Obtaining data

Available data are data that were produced in the past for some other purpose but that may help answer a present question inexpensively. The library and the Internet are sources of available data.

Government statistical offices are the primary source for demographic, economic, and social data (visit http://fedstats.sites.usa.gov/).

Beware of drawing conclusions from our own experience or hearsay. Anecdotal evidence is based on haphazardly selected individual cases, which we tend to remember because they are unusual in some way. They also may not be representative of any larger group of cases.

Some questions require data produced specifically to answer them. This leads to designing observational or experimental studies.