IThm, complexITy, computabilITy> A top-level general strategy which guides other heuristics to search for feasible solutions in domains where the task is hard. Metaheuristics have been most generally applied to problems classified as NP-Hard or NP-Complete by the theory of computational complexITy. However, metaheuristics would also be applied to other combinatorialoptimisation problems for which IT is known that a polynomial-time solution exists but is not practical. Examples of metaheuristics are Tabu Search, {simulated annealing}, {genetic algorIThms} and {memetic algorIThms}. (1997-10-30)