Repeated measurement of the dependent variable is a characteristic of which study design?

• A. Group Designs
• B. Quasi-Experimental Research Designs
• C. Single Subject Research Designs
• D. Qualitative Research Designs

Answer: (C)

Single-subject designs rely on repeated measurement of the same dependent variable over time, across different phases or conditions for the same individual. This steady stream of data lets you see how the behavior changes in response to manipulating the independent variable, providing a clear within-subject picture of cause and effect. By plotting many observations during baseline and during intervention (and sometimes across reversals or multiple baselines), you can demonstrate a functional relationship even with a small number of participants. Group designs, by contrast, emphasize comparing averages across groups, while quasi-experimental and qualitative designs focus on time-stamped or descriptive data in different ways, not the same emphasis on repeated within-subject measurements to establish causality.