Random allocation is a technique for creating the treatment and control groups particularly in accordance of the clinical trial. Subjects receive the active treatment or the placebo on the basis of the outcome of a chance event, for instance, tossing a coin. The method gives an impartial procedure for the allocation of treatments to the individuals, free from the  personal biases, and ensures a firm footing for application of significance tests and most of the rest of the statistical methodology likely to be taken in use. Additionally the technique distributes the effects of concomitant variables, observed and unobserved both, in a statistically acceptable fashion.