Generalization means using a study’s results to describe a larger group. To evaluate a broad claim, compare that group with the people actually studied and ask how they were recruited. People who volunteer may share an interest that others lack. Many positive responses do not make a self-selected sample representative.
Hints
- Hint 1
The target population is everyone the conclusion describes; the sample is only the people studied. Compare the general population with the people who responded to the company’s ad.
- Hint 2
In a voluntary-response sample, people choose themselves for a study instead of being picked by chance. Could an ad about athletic improvement attract people who differ from the general population?
- Hint 3
To generalize is to extend results beyond the people studied. The positive reports tell you what the volunteers said, but do they tell you what people who did not volunteer would experience?
Step-by-step
Check who the volunteers represent
Step 1Identify the two groups
No Desmos needed. This question depends on who entered the study, not arithmetic.
The target population is the group the company wants to describe: the general population. The sample is the group actually studied: the volunteers.
- Step 2
Check how the sample was formed
The ad sought people interested in boosting athletic performance, and the volunteers chose to respond. That makes this a voluntary-response sample: people opted in rather than being picked by chance. Their interest in endurance may differ from that of people who did not volunteer.
- Step 3
Limit the conclusion to what the study supports
The reports tell us what these volunteers said, not what the general population would experience. To extend a result to a population, the sample must represent that population. The volunteers may not represent everyone, so the company cannot generalize its result. Choice B.