snowball sample
n.— «Researchers pursue what is called a “snowball sample,” seeking out workers who then recruit their friends in a process they liken to a chain letter, or to the “six degrees of separation” theory of connectedness. A mathematical formula is applied to the sample like a “corrective lens,” Professor Heckathorn explained, to obtain a sample that is “theoretically independent of its nonrandom starting points.”» —“In Challenge to Survey Low-Wage Workers, Researchers Pursue ’Snowball Sample'” by Sam Roberts New York Times Apr. 15, 2006. (source: Double-Tongued Dictionary)
Further reading
A book of photographs and essays by famous writers celebrates libraries — and the librarians who changed their lives. Plus cutting doughnuts, spinning cookies, and pulling brodies: There are lots of ways to talk about spinning a car in circles on...
Amid a 1796 heat wave, Jane Austen wrote to her sister, “What dreadful hot weather we have! It keeps me in a continual state of inelegance.” This is part of a complete episode. Transcript of “Jane Austen’s Continual State of Inelegance in a...