Binary Information Press
To deal with the problem of the empty or too little answers returned from XML documents, this paper proposes a method of relaxing contextual preference, that is, preferences whose query results depend on the context at the time of their submission. In this paper, firstly, the authors define a contextual preference model in XML. Moreover, they introduce relaxing context operators, which may be produced by relaxing one or more of its context attributes. Furthermore, contextual preferences are stored in a data structure, called the profile tree.