Question

Random-digit dialing is often used to select telephone survey samples. This technique randomly selects the last four digits of a telephone number from a telephone exchange. (An exchange is the first three telephone numbers after the area code). This type of sample gets around the problem of using a telephone book as a sampling frame; however, other types of problems may still be encountered. Identify one type of selection biases that may ensue from this metho

Answer 1

Non-response bias

Explanation:

Selection bias in a survey occurs when individuals are selected in a disproportionate way such that the samples obtained do not represent the true population to be studied or interviewed. An example of a selection bias that can occur from Random-digit dialing is the non-response bias.

Participants who are to be selected for surveys must be eligible or suitable for the purpose of the experiment. If the survey is trying to measure the effect of stress on parents, there is a possibility that through random-digit dialing, homes might be called at times when parents are on a work trip. This inability to get the response of eligible subjects for the survey is a form of selection bias.