Identify the sampling frame the sampling method and any pote

Identify the sampling frame, the sampling method, and any potential sources of bias. For an upcoming school board election, the local newspaper called every 50th household phone number listed in the white pages (directory of land line phone numbers).

Solution

The sampling is by calling every 50th household phone number listen in white pages.

The sampling frame (a list of the items or people forming a population from which a sample is taken) is therefore the set of people whose name is listed in the white pages as only these people will be called.

The sampling method is systematic sampling as every 50-th record from the sampling frame is selected.

The list (in the land-line of telephone directories) has a implicit order - the names are order alphabetically. Therefore, people with names starting from say Q or Z (who will be less in number compared to say S or A) will have a very low chance of being selected.

There is also a bias that the person whose name is alphabetically at the top of the list (of the form AA....) is 100% sure to be selected for the survey.