Problem: A social work researcher attends several different meetings of the Gay and Lesbian Community Center, in which she listens to speakers and introduces herself as a researcher. She identifies several people who seem to know a lot about the gay and lesbian community in Yourtown, including people from two apparently different "factions" within the group, and she asks them for interviews. This sampling procedure is associated with: Group of answer choices Probability sampling Quota sampling Purposive sampling Availability sampling Snowball sampling