Snowball sampling is an approach for locating information-rich key informants (Patton, 1990). Using this approach, a few potential respondents are contacted and asked whether they know of anybody with the characteristics that you are looking for in your research. For example, if you wanted to interview a sample of vegetarians / cyclists / people with a particular disability / people who support a particular political party etc., your initial contacts may well have knowledge (e.g. through a support group) of others (adapted from: http://www.tardis.ed.ac.uk/~kate/qmcweb/s8.htm).
Snowball sampling is not a stand-alone tool; the tool is a way of selecting participants and then using other tools, such as interviews or surveys. Having identified those with the skills and/or knowledge or characteristics you require, you would then approach these people to invite them to participate in a community consultation process.
This page originally copied with permission from the Citizens Science Toolbox.
