Wikipedia Arborification and Stratified Explicit Semantic Analysis

TL;DR

This paper extends Explicit Semantic Analysis by weighting Wikipedia categories, extracting a minimal spanning tree, and introducing stratified tfidf to improve text classification accuracy.

Contribution

It introduces a novel stratified tfidf approach based on a weighted Wikipedia category tree, enhancing semantic analysis for better classification results.

Findings

Increases classification precision by 18%.

Uses minimal spanning tree to structure Wikipedia categories.

Enhances semantic relatedness measurement.

Abstract

[This is the translation of paper "Arborification de Wikip\'edia et analyse s\'emantique explicite stratifi\'ee" submitted to TALN 2012.] We present an extension of the Explicit Semantic Analysis method by Gabrilovich and Markovitch. Using their semantic relatedness measure, we weight the Wikipedia categories graph. Then, we extract a minimal spanning tree, using Chu-Liu & Edmonds' algorithm. We define a notion of stratified tfidf where the stratas, for a given Wikipedia page and a given term, are the classical tfidf and categorical tfidfs of the term in the ancestor categories of the page (ancestors in the sense of the minimal spanning tree). Our method is based on this stratified tfidf, which adds extra weight to terms that "survive" when climbing up the category tree. We evaluate our method by a text classification on the WikiNews corpus: it increases precision by 18%. Finally, we provide hints for future research