Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for index-side synonym expansion are disclosed. Some implementations include actions of obtaining a token sequence for a resource, wherein each token in the token sequence comprises one or more characters. The actions also include selecting a token from the token sequence, wherein the selected token comprises at least one numeric portion having one or more contiguous numeric characters, and at least one non-numeric portion having one or more non-numeric characters. Further actions include generating a new token corresponding to each of the at least one numeric portions of the selected token and storing data associating the selected token and each of the new tokens corresponding to the at least one numeric portion of the selected token as index terms for the resource, wherein the search engine index is accessed to augment search queries.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for synonym verification. In one aspect, a method includes receiving a term and a candidate synonym for the term. The method further includes generating a term group of one or more text strings and a synonym group of one or more text strings. Each text string in the term group corresponding to a translation of the term into a language, and each text string in the synonym group corresponding to a translation of the synonym into the language. The method further includes determining whether the candidate synonym is a valid synonym for the term from an amount of overlap between the term group of text strings and the synonym group of text strings.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for index-side synonym expansion are disclosed. Some implementations include actions of obtaining a token sequence for a resource, wherein each token in the token sequence comprises one or more characters. The actions also include selecting a token from the token sequence, wherein the selected token comprises at least one numeric portion having one or more contiguous numeric characters, and at least one non-numeric portion having one or more non-numeric characters. Further actions include generating a new token corresponding to each of the at least one numeric portions of the selected token and storing data associating the selected token and each of the new tokens corresponding to the at least one numeric portion of the selected token as index terms for the resource, wherein the search engine index is accessed to augment search queries.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for index-side synonym expansion. One method includes indexing a token from a resource, including determining that the token comprises a numeric portion and storing data associating the resource with both the particular token and the numeric portion in a search engine index. Another method includes indexing a token from a resource, including normalizing the token by removing a prefix matching a stopword prefix and storing data associating the resource with both the token and the normalized form of the token in a search engine index. Another method includes creating a token blacklist.