Koetutkimuksen

Koetutkimus, or experimental research, is a methodological approach in which the researcher deliberately manipulates one or more independent variables to observe the effect on dependent variables, while attempting to hold other potential factors constant. The aim is to establish causal relationships rather than mere associations. In Finnish scholarly usage, koetutkimus encompasses laboratory and field experiments across natural sciences, engineering, psychology, and social sciences.

Key designs include true experiments, where participants are randomly assigned to treatment and control groups, allowing strong causal inference, and quasi-experiments, which lack random assignment but use statistical controls to approximate causal effects. In addition, randomized controlled trials (RCTs) are a common form in medicine and clinical psychology, while field experiments test hypotheses in real-world settings. Data collection may involve measurements, behavioral observations, or performance metrics, and analysis commonly relies on inferential statistics.

Conducting koetutkimus requires careful planning: formulating a testable hypothesis, operationalizing variables, selecting the experimental design, and ensuring reliable procedures. Ethical considerations are essential, particularly when human participants are involved; researchers must obtain appropriate ethics approval, informed consent, and minimize risk. Validity concerns include internal validity (controlling for confounders) and external validity (generalizability). Replication and preregistration are increasingly emphasized to improve credibility.

Applications of koetutkimus span many disciplines, from testing scientific theories in laboratories to evaluating the effectiveness of interventions in education and healthcare, and evaluating user experience in software development (A/B testing). The method often complements observational studies and qualitative research to provide a fuller evidence base.