Giving every participant an equal chance of landing in either group is:
- Operational defining
- Naturalistic observation
- Correlational research
- Random assignment
Show answer and solution
Correct answer: D. Random assignment
1. Groups must start out comparable for a comparison to mean anything.
2. With random assignment, all participants have an equal chance of being assigned to either group.
3. That evens out unknown differences between the groups on average.
4. It is what makes a causal conclusion possible.
_Source: OpenStax Psychology 2e (CC BY 4.0), Ch 2 'Psychological Research', sections 2.1-2.4_