Experimental design refers to the structured planning of research studies to test hypotheses, establish relationships, and minimise bias. It determines how variables are manipulated and measured to generate valid and reliable results.
Rooted in scientific methodology, experimental design became formalised in the 20th century through statisticians such as R.A. Fisher. Today, it is used in natural sciences, social sciences, medicine, and business research.
Well-designed experiments provide reliable evidence for theories, treatments, or strategies. They reduce bias, support causality, and enhance reproducibility, ensuring that research findings are trustworthy.