Chapter 4 - Sampling
Replication of research is an important part of the Scientific Method. In order for another researcher to replicate a study, the original author or authors must include specific information about the sampling plan (procedures) used in the study. Refer to some of the mass media journals available to you. Find articles that use samples. Do the articles contain enough information for another researcher to replicate the study?
Compute the maximum estimated sampling error for a sample of 1,400 respondents. Do the same for a sample of 2,400. (Do this by hand. Don't use a sampling error calculator on the Internet.)
The sampling error numbers included in Table 4.4 were computed by using the formula on page 100. Why was the value 1.96 used to compute the values shown in Table 4.4?
Any research project that uses a sample selected from the population involves some amount of sampling error. What type of error is involved if a census is conducted?
Refer to the results of the polls for the presidential election on page 85. The associated sampling error rates are not shown, but considering the sources, an educated guess is that there is a range of about 3% to 5%. With sampling error considered, all of the estimates match the actual vote percentages. Even with this evidence, some people claim that sampling is not an accurate procedure. Why would people make such a claim when the evidence clearly supports that research using samples can predict very closely the outcome of an event such as a presidential election?
Theoretically, mass media research using the scientific method investigates research questions and hypotheses by selecting a random sample from the population. From what you now know, are random samples used in mass media research? That is, are the sample truly random? Why or why not?