No-Free-Lunch theorems

The No-Free-Lunch theorems are a set of theories relating to search algorithms, and their applicability to generic problems.

Introduction

Taking their name from the phrase "there ain't no such thing as a free lunch", these theorems explain why, over the set of all mathematically possible problems, each search algorithm will do on average as well as any other. This is due to the bias in each search algorithm, because sometimes the assumptions that the algorithm makes are not the correct ones.

They are used as an argument against using generic searching algorithms such as Genetic Algorithms and Simulated Annealing without using as much domain knowledge as possible.

External links