Which sampling method occurs when one participant helps the researcher contact others?

• A. Purposive sampling
• B. Snowball sampling
• C. Convenience sampling
• D. Systematic sampling

Answer: (B)

The main idea here is recruitment through referrals within people’s networks. Snowball sampling works by starting with a few participants who meet the study’s criteria, and then each participant helps contact and bring in other individuals who fit the criteria. Those new participants can then refer others, creating a chain of recruitment. This approach is especially useful when the population is hard to reach or not easily identified in a list, because researchers rely on participants’ networks to grow the sample.

This differs from purposive sampling, where researchers intentionally select particular cases for a purpose but don’t rely on participants to recruit others. Convenience sampling picks whoever is easily accessible, not through referrals. Systematic sampling follows a predefined rule to select participants, like every nth person from a list, and is a more formal, probability-based method. Snowball sampling’s distinctive feature is the referral chain started by a participant.