What defines a single-subject research design?

• A. Focus on group data over time
• B. Study of one individual’s behavior over time
• C. Use of randomized controlled trials
• D. Analysis of personality traits

Answer: (B)

A single-subject research design is characterized by its focus on the in-depth study of one individual's behavior over time. This approach allows for the detailed observation and analysis of how specific interventions or conditions affect an individual's behavior, making it particularly useful in the field of behavior analysis.

In this design, repeated measures are taken to assess the individual's reactions to treatments or interventions across different phases, often referred to as baseline and intervention phases. This time-intensive methodology enables researchers to establish causal relationships and understand the variability in individual responses, thereby providing insights that can be tailored to specific needs.

The focus on one individual as opposed to a group allows for a comprehensive understanding of the effects of a treatment and can highlight nuances that group studies may overlook. Consequently, researchers can better identify effective strategies for behavior change and improve outcomes for individuals.

Other options, while relevant in research contexts, do not accurately describe the essence of single-subject research design. For example, focusing on group data over time examines trends in larger populations and lacks the individualized lens that single-subject designs promote. Similarly, randomized controlled trials involve larger samples and aim to generalize findings across groups rather than focus on individual behaviors. Analyzing personality traits typically delves into characteristics of individuals rather than the applied behavioral