# Viterbi semiring

The *Viterbi semiring* has been used in the setting of parsing to give possible parses a *confidence score*. This appears in the work of Goodman.

Tags: Semiring, Scoring, Parsing. References:

- Semiring Parsing (Goodman), introduces the notion of parsing with semirings and, as an example, the Viterbi semiring.
- Monads from Algebra and the the Gray Code from Groups (Sigfpe): http://blog.sigfpe.com/2007/06/, describes the Viterbi algorithm in Haskell and an optimization idea in the next article.