Which research design is characterized by focusing on a single subject or a few subjects to carry out an entire experiment?

The research design that focuses on a single subject or a few subjects to carry out an entire experiment is known as a single subject design. This approach is particularly valuable in fields like psychology and education, where individual differences can significantly impact outcomes. By concentrating on a limited number of subjects, researchers can observe specific behaviors or responses in detail over time, allowing for a thorough examination of the effects of an intervention or treatment on each participant.

Single subject designs are distinguished by their ability to provide rich qualitative and quantitative data that can reveal trends, effectiveness of interventions, and individual variations in response. This design is often implemented using repeated measures, allowing for comparison of behavior before, during, and after interventions. It is especially useful in applied settings, such as therapeutic or educational contexts, where understanding the unique needs of individual clients or students is crucial.