kontrolgruppe

Kontrolgruppe refers to a group of subjects in an experiment that does not receive the experimental intervention being tested. The kontrolgruppe serves as a baseline for comparison, allowing researchers to attribute observed differences in outcomes to the intervention rather than to natural variation, external conditions, or placebo effects.

In randomized controlled trials, participants are allocated to the kontrolgruppe or the experimental group by randomization to reduce selection bias. A control condition may involve a placebo, standard of care, or no treatment, depending on ethical and practical considerations. Blinding procedures—single-blind and double-blind—are often employed to limit bias in outcome assessment and reporting.

Beyond placebo controls, other control types include active controls (a different treatment used for comparison) and historical controls (outcomes drawn from previous observations). The choice of control condition affects interpretation and generalizability of results.

Ethical and methodological limitations include the feasibility of withholding treatment when it is beneficial, the possibility that groups differ in unmeasured factors, and limited external validity in real-world settings. The kontrolgruppe remains a central component of experimental design in medicine, psychology, and social sciences, reinforcing causal inferences when implemented with rigor.