Heuristic

A heuristic is a practical rule or shortcut used to find a workable answer without exhaustively evaluating every possibility. AI systems use heuristics to prioritize search paths, reduce computation, rank candidate actions, or make decisions when complete information is unavailable. A route planner may estimate the remaining distance to a destination, while a game program may score a position before exploring it further. Heuristics can make difficult problems manageable, but they trade certainty for speed and may perform poorly outside the situations for which they were designed. Their assumptions, failure cases, and interaction with learned models should therefore be tested rather than treated as universal truths.