Thematic Cohesion: measuring terms discriminatory power toward themes
Clément
de Groc
author
Xavier
Tannier
author
Claude
de Loupy
author
2014-05
text
Proceedings of the Ninth International Conference on Language Resources and Evaluation (LREC’14)
European Language Resources Association (ELRA)
Reykjavik, Iceland
conference publication
We present a new measure of thematic cohesion. This measure associates each term with a weight representing its discriminatory power toward a theme, this theme being itself expressed by a list of terms (a thematic lexicon). This thematic cohesion criterion can be used in many applications, such as query expansion, computer-assisted translation, or iterative construction of domain-specific lexicons and corpora. The measure is computed in two steps. First, a set of documents related to the terms is gathered from the Web by querying a Web search engine. Then, we produce an oriented co-occurrence graph, where vertices are the terms and edges represent the fact that two terms co-occur in a document. This graph can be interpreted as a recommendation graph, where two terms occurring in a same document means that they recommend each other. This leads to using a random walk algorithm that assigns a global importance value to each vertex of the graph. After observing the impact of various parameters on those importance values, we evaluate their correlation with retrieval effectiveness.
de-groc-etal-2014-thematic
http://www.lrec-conf.org/proceedings/lrec2014/pdf/991_Paper.pdf
2014-05