Abstract: The key to success of the Web-based information management, business intelligence and decision making systerns is high duality information from the Web. However,the Web source duality is very problematic due to the peculiar characteristics of the Web, such as, dynamics and autonomy of Web sources, enormous amount and various types of Web data, multifarious quality requirements of Web applications, etc. There has been some work on Web source quality mamagement In this paper,the quality requirements of advanced Welrbased applications(e. g. business intelligence) and the quality challenges of Web sources were analyzed. The statcofart in Web source quality pattern discovery and evaluation was surveyed. Data mining and the related approaches for dealing with Web duality issues were investigated to reveal many still unsolved problems and to suggest several important research directions.

Key words: Web source quality, Quality pattern mining, Metadata management, Quality evaluation approaches