Comments, with reply, on "Reliability of modified designs-a Bayes analysis of an accelerated test of electronic assemblies" by L. Hart

In examining the above-named work (See ibid., vol.39, June 1990, p.140-4) of L. Hart, the commenter (Ganter) observes that Hart´s choice of a beta prior is reasonable and convenient only because it is well known that a beta prior yields a beta posterior in the Bayes method. It is argued that, because the binomial is exact, Hart can have no real justification for his beta prior from his A test results. Hart presents a reply. In addition, H.F. Martz and R. Fisher comment on the above exchange of views. They conclude that Ganter´s claim that Hart achieved no inference gain in using Bayes methods is unfounded. They argue that Ganter´s conclusion depends on the particular data set chosen and that his choice of ratio is inappropriate.<>