Convenience sampling: Just ask whoever is around.

• Example: “Man on the street” survey (cheap, convenient, often quite opinionated, or emotional => now very popular with TV “journalism”)
• Which men, and on which street?
• Ask about gun control or the legalization of marijuana “on the street” in DC or in some small town in VA and you would probably get totally different answers.
• Even within DC, answers would probably differ if you did the survey in the NW vs the SE.
• Bias: Opinions limited to individuals present.

Poor Sampling methods