Thesaurus Based Term Ranking for Keyword Extraction

In many cases keywords from a restricted set of possible keywords have to be assigned to texts. A common way to find the best keywords is to rank terms occurring in the text according to their tf.idf value. This requires a corpus of texts from which document frequencies can be derived. In this paper we show that we can obtain results of the same quality without the usage of a background corpus, using relations between terms provided in a thesaurus.