1. A non-transitory computer-readable storage medium containing structured data for use with computer program code executing on a computer processor, comprising: a sentiment thesaurus data structure stored in the storage medium and including data used by the computer program code, when executed, to generate one or more valid sentiments related to an indicated input word, the valid sentiments selected based upon an evaluation of a set of rules that define valid sentiments, the data structure comprising: a plurality of sentiment entries, each entry containing an indication of one of a plurality of valid sentiment adjectives that can be used to express one of the valid sentiments applicable to online content, the valid sentiments selected based upon the evaluation of the set of rules that define valid sentiments, an indication of an adjective related to the valid sentiment adjective of the sentiment entry, and a connection type indicator that characterizes a semantic relationship between the related adjective and the valid sentiment adjective that is within a specified permissible degree of distance in meaning, the indicated connection type being one of a plurality of permitted connection types that limit a degree of distance in meaning between adjectives.
5. The computer-readable storage medium of claim 1 wherein the plurality of permitted connection types include semantic relationships that specify a first and a second word having a similar meaning, where the first word is a more specific description of the second word.