Patent ID: 8332207

Claim:
A language model system comprising: one or more computers; and one or more computer-readable storage devices, coupled to the one or more computers, on which are stored: a collection of n-grams, and for each n-gram, a corresponding relative frequency, wherein each n-gram is obtained from a corpus and each relative frequency is the relative frequency of the n-gram in the corpus, each n-gram being a sequence of tokens of length k, wherein k is an integer between 1 and a maximum length N, inclusive; and a set of backoff factors α k , one backoff factor for each value of k from 2 to N, inclusive, wherein every backoff factor is different from every other backoff factor and every backoff factor is a constant, wherein for each value of k from 2 to N, the backoff factors define how to compute a score S k for any n-gram of length k that is not present in the language model, wherein the n-gram of length k that is not present in the language model has a longest backoff n-gram that is present in the language model, and the score S k is defined in accordance with S k = f ⁢ ∏ i = m + 1 k ⁢ ⁢ α i , wherein f is the frequency of the longest backoff n-gram present in the language model and m is the length of the longest backoff n-gram present in the language model.