Although the technology, especially the miniaturization, involved in the combinatorial method (“Combinatorial discovery initiative will speed lab work in three departments,” Sep. 18) may be only 10-12 years old, it is perhaps less well-known that the principle itself dates back to at least 1936 when an early edition of Ronald Fisher’s book “The Design of Experiments” was published. Fisher, a pre-eminent statistician who visited Iowa State, was concerned with operational research in agriculture wherein non-additivities and variabilities are rife, and he used the term `factorial’ rather than `combinatorial’. Even so I would like to suggest that the chapter headed “The factorial design in experimentation” would make interesting reading for students concerned with the development of the Combinatorial Discovery Initiative.

C. Philip Cox

Professor Emeritus

Statistics