The Role of Randomization in Inference

Who is there that has not longed that the power and privilege of selection among alternatives should be taken away from him in some important crisis of his life, and that his conduct should be arranged for him, either this way or that, by some divine power if it were possible, — by some patriarchal power in the absence of divinity, — or by chance even, if nothing better than chance could be found to do it? Anthony TrollopePhineas FinnVol. II, Ch. LX. In the design and analysis of an experiment there are several places where an element of randomization can be used: the design can be selected at random, the result can have a random element adjoined to it, or the random element already present can be used in the analysis. The first technique is much used by statisticians; for example, in making a survey of a population, Basu (1980) calls it prerandomization.