The feature quantity
Akiko Aizawa · 2000
The feature quantity, a quantitative representation of specificity introduced in this paper, is based on an information theoretic perspective of co-occurrence events between terms and documents. Mathematically, the feature quantity is defined as a product of probability and information, and maintains a good correspondence with the tfidf-like measures popularly used in today's IR systems. In this paper, we present a formal description of the feature quantity, as well as some illustrative examples of applying such a quantity to different types of information retrieval tasks: representative term selection and text categorization.