Practice question · Sort into groups
Sort each described sample by whether it generalizes well to the broader population.
Groups: Strong generalizability · Weak generalizability
- Only intro-psych undergraduates at one university
- A stratified sample matching age and region proportions
- 30,000 self-selected online volunteers
- A carefully drawn random sample of 400 from the whole population
Hints
- Generalizability tracks the sampling METHOD, not the raw number of people.
- Random and stratified samples generalize well; convenience samples (even large ones) do not.
Show the answer
Strong generalizability: A carefully drawn random sample of 400 from the whole population, A stratified sample matching age and region proportions
Weak generalizability: 30,000 self-selected online volunteers, Only intro-psych undergraduates at one university
Why
Random and stratified samples generalize well because their selection method controls bias; large self-selected or single-classroom convenience samples generalize poorly despite their size. Method, not headcount, drives external validity.
Practise Sampling Techniques
The app has 5 more questions on this lesson, and keeps your place in the course. Psychology I is free to start.
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