A heuristic (; from Ancient Greek __ εὑρίσκω ( _heurískō )_ 'to find,
discover'), or heuristic technique , is any approach to problem solving or
self-discovery that employs a practical method that is not guaranteed to be
optimal, perfect, or rational, but is nevertheless sufficient for reaching an
immediate, short-term goal or approximation in a search space. Where finding
an optimal solution is impossible or impractical, heuristic methods can be
used to speed up the process of finding a satisfactory solution. Heuristics
can be mental shortcuts that ease the cognitive load of making a decision.
Examples that employ heuristics include using trial and error, a rule of thumb
or an educated guess.