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
Old. Elderly. Senior. Why are we so uncomfortable when we talk about reaching a certain point in life? An 82-year-old seeks a more positive term to describe how she feels about her age. And: a linguist helps solve a famous kidnapping case, using the...
Imagine telling someone how to get to your home, but without using the name of your street, or any other street within ten miles. Could you do it? We take street names for granted, but these words are useful for far more, like applying for a job or...