Being the de-facto standard for data representation and exchange over the Web, XML (Extensible Markup Language) allows the easy development of applications that exchange data over the Web. This creates a set of data management requirements involving XML. XML and related standards have been extensively applied in many business, service, and multimedia applications. As a result, a large volume of data is managed today directly in XML format.
With the wide and in-depth utilization of XML in diverse application domains, some particularities of data management in concrete applications emerge, which challenge current XML technology. This is very similar with the situation that some database models and special database systems have been developed so that databases can satisfy the need of managing diverse data well. In data- and knowledge- intensive application systems, one of the challenges can be generalized as the need to handle imprecise and uncertain information in XML data management by applying fuzzy logic, probability, and more generally soft computing. Currently, two kinds of situations are roughly identified in soft computing for XML data management: applying soft computing for the intelligent processing of classical XML data; applying soft computing for the representation and processing of imprecise and uncertain XML data. For the former, soft computing can be used for flexible query of XML document as well as XML data mining, XML duplicate detection, and so on. Additionally, it is crucial for Webbased intelligent information systems to explicitly represent and process imprecise and uncertain XML data with soft computing. This is because XML has been extensively applied in many application domains which may have a big deal of imprecision and vagueness. Imprecise and uncertain data can be found, for example, in the integration of data sources and data generation with nontraditional means (e.g., automatic information extraction and data acquirement by sensor and RFID). Also XML has been an important component of the Semantic Web framework, and the Semantic Web provides Web data with well-defined meaning, enabling computers and people to better work in cooperation.
Soft computing has been a crucial means of implementing machine intelligence. Therefore, soft computing cannot be ignored in order to bridge the gap between human-understandable soft logic and machine-readable hard logic. It can be believed that soft computing can play an important and positive role in XML data management. Currently the research and development of soft computing in XML data management are attracting an increased attention.