Text Categorization

Synonyms

Text classification

Definition

Text classification is to automatically assign textual documents (such as documents in plain text and Web pages) into some predefined categories based their content. Formally speaking, text classification works on an instance space X where each instance is a document d and a fixed set of classes C = {C₁, C₂, … , C_|C|} where |C| is the number of classes. Given a training set D_l of training documents 〈d, C_i〉 where 〈d, C_i〉 ∈ X × C, using a learning method or learning algorithm, the goal of document classification is to learn a classifier or classification function γ that maps instances to classes: γ : X → C [7].

Historical Background

Text classification, which is to classify documents into some predefined categories, provides an effective way to organize documents. Text classification dates back to the early 1960s, but only in the early 1990s did it become a major subfield of the information systems discipline. Recently, with the explosive growth of...