Studies are often done by pharmaceutical companies to determine the effectiveness of a treatment. Suppose that a new cancer treatment is under study. Of interest is the average length of time in months patients live once starting the treatment. Two researchers each follow a different set of 40 cancer patients throughout this new treatment.
What is the population of this study?
Would you expect the data from the two researchers to be identical? Why or why not?
If the first researcher collected their data by randomly selecting 8 patients from each of 5 local hospitals, which sampling method did they use?
If the second researcher collected their data by choosing 40 patients they knew, what sampling method did they use? What concerns would you have about this data set, based upon the data collection method?
Lee et al., Math in Society, §3.1 Overview of the Statistical Process, Exercise 19