Snowball Sampling

Snowball sampling is a technique used by researchers primarily when they are researching "hidden" populations or subcultures (such as drug users. sex workers, gang members) where normal sampling is impractical. The term "snowball" is used to represent a sampling method that relies on one participant recruiting friends and acquaintances from their own population (the analogy being that the sample size will grow like a snowball rolling downhill). While not considered as dependable a method as conventional sampling methods, it is considered possible to draw some valid conclusions from it and make estimates about the social networking that exists with the group being sampled from.