Key Takeaways

• A population is the group that is the main focus of a researcher’s interest; a sample is the group from whom the researcher actually collects data.
• Populations and samples might be one and the same, but more often they are not.
• Sampling involves selecting the observations that you will analyze.
• Nonprobability samples might be used when researchers are conducting exploratory research, by evaluation researchers, or by researchers whose aim is to make some theoretical contribution.
• There are several types of nonprobability samples including purposive samples, snowball samples, quota samples, and convenience samples.
• Sometimes researchers may make claims about populations other than those from whom their samples were drawn; other times they may make claims about a population based on a sample that is not representative. As consumers of research, we should be attentive to both possibilities.
• A researcher’s findings need not be generalizable to be valuable; samples that allow for comparisons of theoretically important concepts or variables may yield findings that contribute to our social theories and our understandings of social processes.
• In probability sampling, the aim is to identify a sample that resembles the population from which it was drawn.
• There are several types of probability samples including simple random samples, systematic samples, stratified samples, and cluster samples.

Exercises

• Read through the methods section of a couple of scholarly articles describing empirical research. How do the authors talk about their populations and samples, if at all? What do the articles’ abstracts suggest in terms of whom conclusions are being drawn about?
• Think of a research project you have envisioned conducting as you’ve read this text. Would your population and sample be one and the same, or would they differ somehow? Explain.
• Imagine you are about to conduct a study of people’s use of the public parks in your hometown. Explain how you could employ each of the nonprobability sampling techniques described previously to recruit a sample for your study.
• Of the four nonprobability sample types described, which seems strongest to you? Which seems weakest? Explain.
• Find any news story or blog entry that describes results from any social scientific study. How much detail is reported about the study’s sample? What sorts of claims are being made about the study’s findings, and to whom do they apply?
• Imagine that you are about to conduct a study of people’s use of public parks. Explain how you could employ each of the probability sampling techniques described earlier to recruit a sample for your study.
• Of the four probability sample types described, which seems strongest to you? Which seems weakest? Explain.

References

Arnett, J. J. (2008). The neglected 95%: Why American psychology needs to become less American. American Psychologist, 63, 602–614.

Henrich, J., Heine, S. J., & Norenzayan, A. (2010). The weirdest people in the world? Behavioral and Brain Sciences, 33, 61–135.

Holt, J. L., & Gillespie, W. (2008). Intergenerational transmission of violence, threatened egoism, and reciprocity: A test of multiple pychosocial factors affecting intimate partner violence.American Journal of Criminal Justice, 33, 252–266.

Keeter, S., Dimock, M., & Christian, L. (2008). Calling cell phones in ’08 pre-election polls. The Pew Research Center for the People and the Press. Retrieved from https://people-press.org/https://people-press.org/files/legacy-pdf/cell-phone- commentary.pdf

Klawiter, M. (1999). Racing for the cure, walking women, and toxic touring: Mapping cultures of action within the Bay Area terrain of breast cancer. Social Problems, 46, 104–126.

Klawiter, M. (1999). Racing for the cure, walking women, and toxic touring: Mapping cultures of action within the Bay Area terrain of breast cancer. Social Problems, 46, 104–126.

Kogan, S. M., Wejnert, C., Chen, Y., Brody, G. H., & Slater, L. M. (2011). Respondent-driven sampling with hard-to-reach emerging adults: An introduction and case study with rural African Americans. Journal of Adolescent Research, 26, 30–60.

Nagae, M., & Dancy, B. L. (2010). Japanese women’s perceptions of intimate partner violence (IPV). Journal of Interpersonal Violence, 25, 753– 766.

Neuman, W. L. (2007). Basics of social research: Qualitative and quantitative approaches (2nd ed.). Boston, MA: Pearson.

Newsweek magazine published an interesting story about Henrich and his colleague’s study: Begley, S. (2010). What’s really human? The trouble with student guinea pigs. Retrieved from https://www.newsweek.com/2010/07/23/what-s-really- human.html

Van Allen, S. (2011). Gallup corporate history. Retrieved from https://www.gallup.com/corporate/1357/Corporate- History.aspx#2