Experimental research design, which can otherwise be called hypothesis-testing research design, were originally made by R.A. Fisher in agricultural research in England. Experimental research design is generally used in experimental studies where hypotheses are tested. Experimental research design is now used in almost all the areas of scientific studies.
The principles of experimental research design which Fisher prescribed are, viz.: (a) the principle of replication, (b) principle of randomization, and (c) the principle of local control.
- The principle of replication suggests that the experiment must be repeated also that the treatment is applied in many experimental units. This increases the statistical accuracy of the experiments.