¶ abductive reasoning

Interestingly, Sherlock Holmes is famously associated with the art of deduction. However, his methods typically illustrate a third type of reasoning, called abductive reasoning. Abductive reasoning describes the inference of the most likely explanation based on novel, observed details that do not fit an existing model. It's non-linear; it does not start with any suppositions or hypotheses, but starts from a state of openness to all forms of data and are then synthesized into a theory or theories. Theories, then, develop into an explanatory insight.

Abductive reasoning is powerful, but it's also very fallible; the expert practitioner relies on their experience to guide them toward insights that are viable and worthwhile.

This is the approach most frequently taken by medical professionals, who must make their best guess based on what incomplete information is available to them.

CS Peirce suggested that abductive reasoning is the only mode of reasoning that is appropriate to complex, wicked problems, as abductive reasoning is most capable of incorporating novel insights or knowledge.

Roger Martin identifies a capacity for abductive reasoning as a key quality of integrative thought.

inductive-reasoning develops a cogent position or hypothesis that is likely true given available data
deductive-reasoning begins with a general theory and then tests against data to prove or disprove it
ooda-loop is a decision-making concept that relies heavily on abductive reasoning in its observe and orient phases