Yksittäistapaustutkimus

Yksittäistapaustutkimus, known in English as a single-case study or single-subject experimental design, is a research methodology used to systematically investigate the effect of an intervention on a single individual or a small group of individuals. It is characterized by repeated measurement of the dependent variable before, during, and after the introduction of an independent variable. The core principle is to establish a baseline behavior and then observe how that behavior changes when an intervention is applied.

This research design typically involves a series of phases. The first phase is the baseline phase (A), where the behavior is measured without any intervention. Following this, an intervention is introduced, and the behavior continues to be measured during the intervention phase (B). If the intervention is removed, a withdrawal phase (A) may follow to see if the behavior reverts to baseline levels. More complex designs can involve multiple interventions (e.g., ABA, ABAB, ABC) or multiple baseline designs across different behaviors, settings, or individuals.

The strength of yksittäistapaustutkimus lies in its ability to demonstrate a functional relationship between the intervention and the observed changes in behavior within a specific individual. It allows for in-depth understanding of the intervention's impact and can be particularly useful in clinical settings, education, and rehabilitation when larger-scale studies are not feasible or appropriate. However, its generalizability to other individuals is limited due to its focus on a single case.