A review and analysis of commercial user modeling servers for personalization on the World Wide Web

The aim of this article is to present and discuss selected commercial user modeling systems against the background of deployment requirements in real- world environments. Following the recent trend towards personalization on t he World Wide Web, these systems are mainly aimed at supporting e-commerce including customer relationship management. In order to guide and structure our review, we define a requirements catalogue that comprises the main dim ensions of functionality, data acquisition, representation, extensibility a nd flexibility integration of external user-related information, compliance with standards, concern for privacy, and system architecture. Apart from t he novelty of such a comparison both inside and outside the classical user modeling literature, a presentation of the core features of these commercia l systems may provide a source of information and inspiration for the desig n, implementation, and deployment of future user modeling systems in resear ch and commercial environments.