Textual features for corpus visualization using correspondence analysis

• Published in: Intelligent data analysis 2009-01, Vol.13 (5), p.795-813
• Main Authors: Petrović, Saša, Dalbelo Bašić, Bojana, Morin, Annie, Zupan, Blaž, Chauchat, Jean-Hugues
• Format: Article
• Language: English
• Subjects: Mathematics; Statistics; Statistics Theory
• ISSN: 1088-467X; 1571-4128
• DOI: 10.3233/IDA-2009-0393

Explorative data analysis in text mining essentially relies on effective visualization techniques which can expose hidden relationships among documents and reveal correspondence between documents and their features. In text mining, the documents are most often represented by feature vectors of very high dimensions, requiring dimensionality reduction to obtain visual projections in two- or three-dimensional space. Correspondence analysis is an unsupervised approach that allows for construction of low-dimensional projection space with simultaneous placement of both documents and features, making it ideal for explorative analysis in text mining. Its present use, however, has been limited to word-based features. In this paper, we investigate how this particular document representation compares to the representation with letter n-grams and word n-grams, and find that these alternative representations yield better results in separating documents of different class. We perform our experimental analysis on a bilingual Croatian-English parallel corpus, allowing us to additionally explore the impact of features in different languages on the quality of visualizations.