Organizational charts (departments, sub-departments, sub-sub-departments, and so on), project work breakdown structures (tasks, subtasks, work packages, etc.), discussion forums (posting, response, response to response, etc.), family trees (parent, child, grandchild, etc.), manufacturing bill-of-material, product classifications, and document…

The concept of a hierarchy of evidence is useful in rapid electronic searching to answer questions arising during the natural course of clinical practice. The answerable question often begins "What is the evidence that ..." and, when focused on a treatment, usually includes a population, an intervention, a comparison group, and an outcome, often…