What is a potential outcome for participants who are randomly assigned to groups in an experiment?

The correct answer highlights that randomly assigning participants to groups in an experiment leads to more valid comparisons between those groups. This is because random assignment helps to ensure that each participant has an equal chance of being placed in any group, which minimizes the influence of pre-existing differences among participants. By doing so, any observed differences in outcomes can be more confidently attributed to the experimental manipulation rather than to other variables that may vary between groups.

In contrast, bias in results due to selection, which suggests that systematic differences could emerge based on how participants are assigned, is mitigated through random assignment. Similarly, the issue of confounding variables—factors that could influence both the independent and dependent variables—is less of a concern when participants are randomly assigned, as this process helps balance these potential confounders across groups. Higher dropout rates are not inherently a result of random assignments; rather, they can vary widely for many reasons unrelated to the method of assignment. Overall, random assignment is a crucial aspect of experimental design that contributes to the integrity and validity of the study's findings.