Design of experiments

Summary

Design of experiments is the part of statistics that plans how data are collected when the experimenter controls the conditions. Its aim is to answer the questions of interest validly and efficiently. Its three classical principles, set out by Ronald Fisher, are randomization, replication and local control by blocking. Its main designs include completely randomized and block designs, Latin squares, factorial and fractional factorial designs, and response surface designs. Optimal experimental design chooses designs that make the estimates as precise as possible, and the data are usually analysed by analysis of variance.