1. “Monitoring the Future” discussed the design, methods, and field procedures for
assessing adolescent substance abuse in the U.S. Given the information on sampling
that was provided, is an appropriate sample size used? Why or why not?
2. Why is a random sample used in this research?
3. What alternate methods could be used to recruit subjects?
4. Is this the most appropriate way to assess adolescent substance use? Justify your
answer.
5. How might you be able to triangulate the results from the “Monitoring the Future”
study?
1. “Women and Parole” details the design, methods, procedures, and results of a study
of female parole agents in California. Given the information on sampling provided, is
an appropriate sample size used? Why or why not?
2. Why is a convenience sample used in this research?
3. What alternate methods could be used to recruit subjects?
4. Is this the most appropriate way to access female parole agents? Justify your answer.
5. How might you be able to triangulate the results from the “Women in Parole” study?
Sample Answer
That's a great exercise in evaluating research methodology! Since the prompt asks for an analysis of two separate studies—"Monitoring the Future" and "Women and Parole"—I'll address each one independently.
1. Analysis of the "Monitoring the Future" Study
The "Monitoring the Future" (MTF) study is a highly respected, ongoing epidemiological survey assessing trends in adolescent substance abuse in the U.S.
Is an appropriate sample size used? Why or why not?
Yes, an appropriate sample size is used. The MTF study typically surveys 40,000 to 50,000 students annually across approximately 400 secondary schools.
Why it's appropriate: For large-scale national surveys aiming to detect relatively small changes in prevalence across diverse demographic groups (e.g., specific age groups, geographic regions, racial/ethnic backgrounds), a large sample size is necessary to achieve sufficient statistical power and keep the margin of error low. Since MTF reports data at the national level and for various subgroups, the large size ensures the findings are generalizable and statistically reliable for detecting trends over time.
2. Why is a random sample used in this research?
MTF uses a highly structured, multi-stage probability (random) sampling technique (selecting schools first, then classes/students).
Reason for use: A random sample is crucial for ensuring the results are representative of the entire target population, which in this case is all 8th, 10th, and 12th-grade students attending regular public and private schools in the continental U.S. Random sampling minimizes selection bias and allows researchers to generalize the findings to the broader population with a known level of confidence (statistical inference).
3. What alternate methods could be used to recruit subjects?
Alternate sampling methods could be used, but they would introduce limitations:
Convenience Sampling: Surveying only students at schools willing to participate near the research institution. This is easy but severely lacks generalizability.