Research Methodology
Snowball Sampling
A non-probability sampling technique where existing study subjects recruit future subjects from among their acquaintances.
What is Snowball Sampling?
Snowball sampling begins with a small pool of initial informants who meet the research criteria. These informants then nominate or recruit others who also meet the criteria, causing the sample to grow like a rolling snowball.
Why Snowball Sampling Matters
It is one of the only viable methods for reaching hidden, marginalized, or stigmatized populations (e.g., illicit drug users, undocumented workers) who lack a sampling frame.
Example
A sociologist studying underground street racing networks interviews one driver and asks them to introduce the researcher to other drivers in the network.
Common Mistakes
- Ignoring that the sample becomes highly interconnected and biased towards individuals with larger social networks.
- Failing to protect participant anonymity when relying on peer referrals.