2.2.3 Avoiding Bias

A common way to collect information about a population is to conduct a survey. That is, a researcher asks questions of a randomly selected sample from the population. Conducting a survey raises problems that can be surprisingly tricky to resolve. Consider how we phrase our questions. Is there bias in the phrasing that might lead participants to answer the questions in a certain way? Are any questions worded ambiguously? If some of the people in the sample interpret a question one way, and others interpret it differently, the survey's results will be meaningless.

Surveyors wish to get as high a response rate as possible. Low response rates can introduce bias if the non-respondent's answers would have differed from those who respondedthat is, if the non-respondents and the respondents represent different segments of the population. If we do not represent a segment of the population, then our sample is not representative of the population. If resources are limited, it is often better to take a small sample and relentlessly pursue a high response rate than to take a larger sample and settle for a low response rate. If we have a low response rate, we should contact non-respondents and try to either increase the response rate or demonstrate that the non-respondents' answers do not differ from the respondents' answers.

Question: In addition to the way we phrase questions, the method of surveying can also introduce bias. What are some potential biases that could occur when using the following survey techniques?

• In-person
• Mail
• Phone
• E-mail
• Text
• Social Media

Please make sure you consideramong other thingshow expensive each method is, the outreach potential, response time, and response rate.