Informal test-ordering protocols that do not follow a physiological rationale are common in teaching hospitals and represent part of the folklore of resident practice. Such faulty test-ordering routines increase the cost of care, waste resources, may fail to answer diagnostic questions, or may generate false leads. They prove to be part of a broader set of issues in information management not restricted to medicine. Clinically appropriate algorithms for diagnostic testing can be constructed to replace folkloric protocols. This should represent a major area of professional concern in clinical pathology.