# between-subjects designs

## Testing Between-Subjects Contrasts in R

Between-Subjects Factors A between-subjects factor refers to independent groups that vary along some dimension. Put another way, a between-subjects factor assumes that each level of the factor represents an independent (i.e., not correlated) group of observations. For example, an experimental factor could represent 2 independent groups of participants who were randomly assigned to either a control or a treatment groupition. In this case, the between-subjects experimental factor assumes that measurements from both groups of participants are not correlated – they are independent.