identify the sampling techniques used, and di...

identify the sampling techniques used, and discuss potential sources of bias (if any). explain.\nin 1965, researchers used random - digit dialing to call 900 people and ask what obstacles kept them from attending town - hall meetings.\nwhat potential sources of bias were present, if any? select all that apply.\na. individuals may have not been available when the researchers were calling. those individuals that were available may have not been representative of the population.\nb. telephone sampling only includes people who had telephones. people who owned telephones may have been older or wealthier on average, and may not have been representative of the entire population.\nc. if there was a regular pattern to the numbers dialed, it is possible for the sample to not have been representative of the population.\nd. individuals may have refused to participate in the sample. this may have made the sample less representative of the population.\ne. there were no potential sources of bias.

Answer

# Brief Explanations: A: Availability bias (unavailable individuals may differ from available ones). B: Sampling frame bias (1965 telephone owners may not represent all, e.g., wealth/age). D: Non-response bias (refusals can make sample unrepresentative). C is invalid as random digit dialing avoids regular patterns. E is incorrect due to A, B, D. # Answer: A. Individuals may have not been available when the researchers were calling. Those individuals that were available may not have been representative of the population., B. Telephone sampling only includes people who had telephones. People who owned telephones may have been older or wealthier on average, and may not have been representative of the entire population., D. Individuals may have refused to participate in the sample. This may have made the sample less representative of the population.