ABSTRACT
In a plant-scale experiment on the production of a certain chemical, a batch of intermediate product was divided into six equal portions which were then processed on successive days by two different methods, P1 and P2. The order of treatment and the yields are given in Table F.1. It was expected that superimposed on any process effect there would be a smooth, roughly parabolic trend. Experience of similar experiments showed that the standard deviation of a single observation was about 0 .1.
