Sampling Frames

Why Use Sampling Frames?

It would be best for a researcher to study an entire population, as a researcher would have results based on every single person. The researcher would not have to make statistical inferences based on a sample or a subset of the population [Page 1547]and thus would not have to worry about statistical error. For example, if a researcher wanted to compare the test scores of the students in classroom A versus the students in classroom B, the ideal situation is to study the population. The population in this case would be a list that includes test scores from every single student in classroom A and in classroom B. However, in most cases a researcher is not going to find this ideal situation. It is likely that at least one student was sick and missed the exam and thus the researcher will have an incomplete list of test scores. Seeing that the list is incomplete, the researcher cannot study the entire population. The researcher can, however, use the sampling frame (the incomplete list of test scores), choose a smaller subset or sample chosen to represent the population, and study the test scores using statistics and make inferences about the entire population.

In other cases it may be impossible to contact all of the people that make up a particular population of interest. For example, if a researcher wants to study all of the twins in the United States, the researcher would quickly find out that it would be impossible to find and study all of these people. This is because there is not a single list that has all of the names and contact information for these people.

To study this population, the researcher would have to try to create the list of names and contact information by doing something like using birth records and corresponding telephone book entries. While the researcher will be able to find many people, there will be many missing from the population. For instance, the researcher may be able to find birth records for all of the twins in the United States, but some of the people may have moved and thus are not listed in the telephone book. The shorter list of people the researcher is able to put together is the sampling frame for the study. The researcher can use this list as the sampling frame, take a sample, and use statistical analysis to make inferences about the population.

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