6. A non-transitory computer-readable medium having computer-readable program instructions stored therein, the computer-readable program instructions configured to, when executed by a computer, cause the computer to: build a span query relevant to a feature and a sentiment about the feature by: building syntactic templates from a lexicography relevant to the feature and the sentiment about the feature, wherein each syntactic template corresponds to multiple phrasings of the same meaning; and determining a first semantic template relevant to the syntactic templates; receive a document; apply the span query to the document to generate a span query result, wherein the span query result includes a quotation from the document relevant to the feature and the sentiment about the feature, the quotation satisfying the first semantic template and including words within relative positions as constrained by the span query; and store the span query result.
6. A non-transitory computer-readable medium having computer-readable program instructions stored therein, the computer-readable program instructions configured to, when executed by a computer, cause the computer to: build a span query relevant to a feature and a sentiment about the feature by: building syntactic templates from a lexicography relevant to the feature and the sentiment about the feature, wherein each syntactic template corresponds to multiple phrasings of the same meaning; and determining a first semantic template relevant to the syntactic templates; receive a document; apply the span query to the document to generate a span query result, wherein the span query result includes a quotation from the document relevant to the feature and the sentiment about the feature, the quotation satisfying the first semantic template and including words within relative positions as constrained by the span query; and store the span query result. 7. The non-transitory computer-readable medium of claim 6 wherein the computer-readable program instructions are further configured to, when executed by the computer, cause the computer to apply a heuristic model to the document.