What term describes the process of randomly assigning participants to different groups to minimize differences?

The process of randomly assigning participants to different groups is known as random assignment. This technique is crucial in experimental research as it helps ensure that each participant has an equal chance of being placed in any group, thereby minimizing pre-existing differences between the groups. By doing so, random assignment enhances the internal validity of an experiment, making it more likely that any observed effects can be attributed to the treatment or intervention being studied, rather than to confounding variables.

In contrast, systematic assignment involves using a fixed strategy to assign participants to groups, which may not sufficiently balance characteristics across those groups. Matched assignment involves pairing participants based on specific traits before randomly assigning them to groups, which adds complexity and may not equally distribute unmeasured variables. Stratified assignment, on the other hand, involves dividing participants into subgroups based on certain characteristics before assignment, which can skew randomization and potentially introduce bias. Therefore, random assignment stands out as the most effective method for creating comparable groups in psychological research.