What effect does random assignment of participants have on the memory study?

Random assignment of participants is a critical aspect of experimental design, particularly in psychological research. When participants are randomly assigned to different groups, it helps ensure that each group is comparable at the outset of the experiment. This process effectively minimizes the influence of confounding variables and individual differences that could otherwise skew the results.

By increasing internal validity, random assignment allows researchers to draw more accurate conclusions about the causal relationships between variables. In the context of a memory study, this means that any observed differences in word recall can be more confidently attributed to the experimental manipulation rather than other factors. As a result, the integrity and reliability of the findings are strengthened, making it more likely that the effects seen in the study are due to the variables being tested, rather than external influences or pre-existing differences among participants. Internal validity is crucial for establishing a cause-and-effect relationship, distinguishing true experimental findings from mere correlations.