Yates's Notation

Yates's notation, named for Frank Yates, is, like the ruler, so useful and so seemingly natural that it is difficult to imagine what researchers did before its invention. Yates's notation indicates the factor levels of treatments in two-level experiments, predominantly but not exclusively, factorial and fractional factorial experiments.

Let each factor in a two-level experiment be denoted by a capital letter. The levels of each factor might be thought of as high and low. For a specific treatment in the experiment, in Yates's notation, one writes the lowercase letter of each factor that is set at the high level and no letter for each factor set at the low level. The treatment with all factors at their low levels is denoted by (1). See Table 1 ...