ABSTRACT
The foundations of the statistical approach to experimentation were laid by R.A. Fisher in the early 1930s. The subject evolved in agriculture but is now applicable to almost all sciences, to engineering and to some arts. The aim of an experiment is to compare a number of treatments on the basis of the responses produced in the experimental material. In agriculture the treatments may be varieties of wheat or different fertilizers, in engineering they may be temperature levels and in a chemical experiment the purpose may be to compare several catalysts. The confidence and accuracy with which treatment differences can be assessed will depend to a large extent on the size of the experiment and on the inherent variability in the experimental material. Dividing the material into relatively homogeneous blocks is an important technique for improving the precision of an experiment.
