1. A computer implemented method for classifying a document comprising the steps of: providing a lexicon comprising one or more lexicon terms wherein the one or more lexicon terms are each members of one or more categories and are associated with category information, identifying a document comprising one or more document terms, comparing the one or more document terms with the one or more lexicon terms, determining which, if any, of the one or more document terms match the one or more lexicon terms, calculating a score for each of the one or more categories using the matched terms and the category information associated with corresponding lexicon terms, and outputting a result of the calculating step.