How does random sampling differ from random assignment?

Random sampling and random assignment are two essential concepts in experimental research that serve different purposes. Random sampling refers to the method used to select participants for a study from a larger population, ensuring that every individual has an equal chance of being included. This process helps achieve a representative sample that reflects the larger population, reducing selection bias and enhancing the generalizability of the study's findings.

On the other hand, random assignment occurs after participants have been selected and involves randomly designating individuals into different treatment or control groups within an experiment. This process ensures that each group is comparable and that any differences observed in outcomes can be attributed to the treatment rather than pre-existing differences among participants. Random assignment is crucial for establishing causal relationships, as it helps mitigate the influence of confounding variables.

The correct distinction emphasizes that random sampling focuses on the selection of participants, while random assignment is about the allocation of those selected participants into different groups. This differentiation is fundamental to understanding the design and validity of experimental research.