The Supreme Court's ruling in Rhodes implies a concrete role of expertise -- research in which physical and mental health of inmates are reviewed and the origin of undesirable findings is traced to conditions of incarceration. Such research, however, is rarely done and experts instead rephrase the question and argue by analogy. Where research is conducted, the results are usually not clear-cut because inmates, like the rest of the population, are disquietingly resilient. The paper discusses minimum standards as one way to circumvent complexities inherent in assessing prison conditions, but concludes that additional data on effects of prison are more desirable. The concluding analysis of expert testimony in eighth amendment cases emphasizes that, in Rhodes v. Chapman, correctional agency staff who were armed with data triumphed over experts who were not.