1. Do now
Do now is posted on google classroom

2. Lesson 3.5
Sampling and Surveys

3. Objectives Explain how undercoverage can lead to bias.
Explain how nonresponse can lead to bias.
Explain how other aspects of a sample survey can lead to bias.

4. Definitions
Undercoverage: some people can’t be chosen or are less likely to be chosen (ex. Landlines)
Nonresponse: people can’t be reached or refuse (ex. No answer, hang up)
Response bias: Interviewer influences answer, wording of questions, people lie
These all lead to bias!

5. *Voluntary response bias is when an invitation to be part of a survey is given and people decided whether or not to participate.  They were NOT specifically chosen by the researchers.
*Nonresponse is when people ARE chosen by the researchers for the survey but the people do not complete the survey.

6. Quiz next class on