an adjective that indicates that the following analysis will be exhaustive and require significant effort, as in, “We need to do a bottom-up look at those valuation models”; depending on context may mean starting from scratch or evaluating something from its most elemental components, in a form of inductive reasoning; used when the hypotheses or principles that would support a top-down, deductive reasoning approach are deficient or cannot be determined; can also be used to give listeners confidence that the referenced work has been thorough and no pertinent details have been overlooked