Identify the sampling techniques used, and discuss potential sources of bias(if any). Explain.Using random digit dialing, researchers call 1400 people and ask what obstacles keep them from voting.

What type of sampling is used?

A. Simple random sampling is used, since each number has an equal chance of being dialed, so all samples of 1400 phone numbers have an equal chance of being selected.

B. Convenience sampling is used, since the 1400 phone numbers that are easiest to reach are selected.

C. Cluster sampling is used, since the phone numbers are divided into groups, several groups are selected, and each number in those groups is called.

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

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. The sample only consists of members of the population that are easy to get. These members may not be representative of the population.

C. Telephone sampling only includes people who have telephones. People who own telephones may be older or wealthier onaverage, and may not be representative of the entire population.

D. Individuals may refuse to participate in the sample. This may make the sample less representative of the population.

E. There are no potential sources of bias.