Final answer:
Random assignment is a critical component of experimental design that helps control subject differences in experimental and control groups. It involves assigning participants randomly to different groups, ensuring equal representation.
Step-by-step explanation:
Random assignment is a critical component of experimental design. It involves assigning participants in a study to different groups (such as experimental and control groups) randomly, ensuring that each participant has an equal chance of being placed in either group. By using random assignment, researchers can control for subject differences between groups, which helps eliminate the possibility that any observed differences in outcomes are due to preexisting differences between the groups.