What is the primary goal of random assignment in research?

The primary goal of random assignment in research is to minimize preexisting differences among participants in different experimental groups. By randomly assigning individuals to groups, researchers ensure that each participant has an equal chance of being placed in any group. This process helps to create equivalent groups in terms of various characteristics such as demographics, personality traits, and any other confounding variables that could influence the outcome of the study.

As a result, random assignment enhances the internal validity of the experiment, allowing researchers to make more reliable conclusions about the effects of the independent variable on the dependent variable. This method is particularly crucial in experimental designs, where the objective is to establish causal relationships and reduce the likelihood that observed effects are due to other factors rather than the treatment itself.

In contrast, simply increasing the sample size, addressing dropout rates, or introducing bias does not effectively control for preexisting differences and can compromise the integrity and results of the research. Therefore, random assignment serves as a fundamental technique to uphold the scientific rigor of experimental studies.