What type of variance is the result of the independent variable and typically found in between-group designs?

The correct answer is systematic variance. This term refers to the portion of the total variance in the dependent variable that can be attributed to the differences in the independent variable. In between-group designs, participants are divided into different groups, with each group receiving a different level of the independent variable. The differences observed in the outcomes between these groups represent systematic variance because they are intentionally manipulated by the researcher.

In this context, systematic variance is what researchers seek to maximize as it indicates that the independent variable is having a significant effect on the dependent variable. In contrast, error variance and random variance pertain to the variability that cannot be accounted for by the independent variable and may arise from individual differences or other extraneous factors affecting the outcomes. Understanding systematic variance is crucial for interpreting the results of experiments, as it helps determine the effectiveness of the manipulations applied.