A Comparison of Text Categorization Methods

Abstract

In this paper firstly I have compared Single Label Text Categorization with Multi Label Text Categorization in detail then I have compared Document Pivoted Categorization with Category Pivoted Categorization in detail. For this purpose I have given the general definition of Text Categorization with its mathematical notation for the purpose of its frugality and cost effectiveness. Then with the help of mathematical notation and set theory ,I have converted the general definitions of Single Label Text Categorization and Multi Label Text Categorization into their respective mathematical representation .Then I discussed Binary Text Categorization as a special case of Single Label Text Categorization. After comparison of Single Label Text Categorization with Multi Label Text Categorization, I found that Single Label Text Categorization or Binary Text Categorization is more general than Multi Label Text Categorization. Thereafter I discussed an algorithm for transformation of Multi Label Classification into Binary Classification and explained the conditions of transformation of Multi Label Classification into Binary Classification. In the second step I compared Document Pivoted Categorization with Category Pivoted Categorization in detail. After comparison we found that Category Pivoted Categorization is more typical and complex than Document Pivoted Categorization. The Category Pivoted Categorization becomes more complicated when new category is added to predefined set of categories and the recurrent classification of documents takes place. Finally I compared Hard Categorization with Ranking Categorization. After comparing them I found that Hard Categorization incorporates ‘Hard Decisions’ about the relevance or belonging of a document to a category. This hard decision is either completely true or completely false. Whereas the Ranking Categorization creates a belonging of a document to a category according to the estimated appropriateness to the document. The final Ranked List is developed in the Ranking Categorization which is used by the human expert for final decision of Text Categorization.