A beam search is a heuristic search technique that combines elements of breadth-first and best-first searches. Like a breadth-first search, the beam search maintains a list of nodes that represent a frontier in the search space. Whereas the breadth-first adds all neighbors to the list, the beam search orders the neighboring nodes according to some heuristic and only keeps the n best, where n is the beam size. This can significantly reduce the processing and storage requirements for the search.

In machine learning, the beam search has been used in algorithms, such as AQ11 (Dietterich & Michalski, 1977).

Cross References

Learning as Search