Identify the sampling techniques used and discuss potential

Identify the sampling techniques used, and discuss potential sources of bias (if any). Explain. Using random digit dialing, researchers call 1500 people and ask what obstacles keep them from saving for retirementsaving for retirement. What type of sampling is used?

A. Systematic sampling is used, since phone numbers are selected from a list using a fixed interval between phone numbers.

B. Simple random sampling is used, since each number has an equal chance of being dialed, so all samples of 1500 phone numbers have an equal chance of being selected. Your answer is correct.

What potential sources of bias are present, if any? Select all that apply. A. Individuals may not be available when the researchers are calling. Those individuals that are available may not be representative of the population. B. Individuals may refuse to participate in the sample. This may make the sample less representative of the population. C. The sample only consists of members of the population that are easy to get. These members may not be representative of the population. D. Telephone sampling only includes people who have telephones. People who own telephones may be older or wealthier on average, and may not be representative of the entire population. E. There are no potential sources of bias.

Solution

1) Since the numbers are randomly dialled, a SRS is used. (option B)

2)

As far as the bias is concerned, we are only targeting the people who have telephones and not everyone. This may affect the sample taken as explained in option D.

Thus, option D is correct for that.

Hope that helps.