ABSTRACT
This chapter presents some techniques that the editor could use to ensure a scheme for comparing the automobiles that is reasonable but yields a fair comparison of the vehicles. It explores incidence matrices for two purposes and describes them to construct some specific block designs. The chapter utilizes them to prove some general results about block designs. Suppose a magazine editor wishes to obtain a fair and reasonable comparison of seven automobiles by assessing the opinions of seven test-drivers. Suppose a magazine editor wishes to compare seven different automobiles by assessing the opinions of seven test-drivers with regard to a variety of topics such as handling and comfort. One way for the editor to obtain a fair comparison of the automobiles would be to have each of the test-drivers evaluate each of the vehicles. However, because of time or monetary constraints, it may not be reasonable for the editor to have each of the test-drivers evaluate each of the vehicles.
