Difference between random assignment and sampling?

Difference between random assignment and sampling?

• A. Random sampling involves how participants are selected; random assignment involves how participants are assigned to a group
• B. Random sampling involves assigning groups; random assignment involves selecting participants
• C. Random sampling and random assignment are the same
• D. Random sampling reduces bias; random assignment increases sample size

Answer: (A)

Random sampling determines who from the population is included in the study, while random assignment determines which of those participants go into which experimental group. This matters because sampling affects generalizability to the population (external validity), while assignment affects the fairness of group comparisons and the ability to draw causal conclusions (internal validity). So, the best description is that sampling is about selecting participants from the population, and assignment is about placing those participants into groups after they've been selected. The other statements mix up roles, claim they’re the same, or misstate effects like changing sample size, which aren’t accurate.

Random sampling determines who from the population is included in the study, while random assignment determines which of those participants go into which experimental group. This matters because sampling affects generalizability to the population (external validity), while assignment affects the fairness of group comparisons and the ability to draw causal conclusions (internal validity). So, the best description is that sampling is about selecting participants from the population, and assignment is about placing those participants into groups after they've been selected. The other statements mix up roles, claim they’re the same, or misstate effects like changing sample size, which aren’t accurate.