In the fall of 2004, after severe flooding in a town, a dog was found and brought to the Humane Society by a woman who expressed her willingness to adopt the dog if its owner could not be located. The dog initially failed their so-called "pinch test" by biting an evaluator who applied pressure to its toes, and so it was not released to the woman until 2 months later. After the incident was publicized in the local newspaper, the paper's Pet tales columnist reported: "I received more than 200 phone calls and e-mails from people who thought this was wrong. Only three defended the shelter."7 Was this a self-selected sample, a stratified sample, or a cluster sample?