Heuristic

A heuristic is a method to help to solve a problem, commonly informal. It is particularly used for a method that often rapidly leads to a solution that is usually reasonably close to the best possible answer. Heuristics are "rules of thumb", educated guesses, intuitive judgments or simply common sense.

In more precise terms, heuristics stand for strategies using readily accessible, though loosely applicable, information to control problem-solving in human beings and machines.

Here are a few commonly used heuristics, from Polya's classic How to Solve It:

• Look to the unknown.^{[dubious – discuss]}
• If you are having difficulty understanding a problem, try drawing a picture.
• If you can't find a solution, try assuming that you have a solution and seeing what you can derive from that ("working backward").
• If the problem is abstract, try examining a concrete example.
• Try solving a more general problem first (the "inventor's paradox": the more ambitious plan may have more chances of success).