In a recent article by P.G. Frankl and E.J. Weyuker (see ibid., vol.19, no.3, p.962-75, 1993), results are reported that appear to establish a hierarchy of software test methods based on their respective abilities to detect faults. The methods used by Frankl and Weyuker to obtain this hierarchy constitute a new and important addition to their arsenal of tools. These tools were developed specifically to establish simple, useful comparisons of test data generation methods. This is the latest step in an ambitious test method classification program undertaken by the Frankl and Weyuker and their collaborators. The article discusses the method and goes on to present a reply to the critique.