A psychology professor recruits 80 student volunteers from her introductory class and randomly assigns 40 to a meditation group and 40 to a control group. After 4 weeks she compares stress levels.
Which scope of inference is appropriate?
- A
Neither inference is justified
- Bcheck_circle
Cause-and-effect inference for the volunteers, but not generalization beyond them
- C
Both cause-and-effect and generalization
- D
Generalization only
Explanation
Volunteers are not a random sample, so we cannot generalize beyond the volunteers. However, random assignment allows causal conclusions for these particular subjects.