Although keyword query enables inexperienced users to easily search XML database with no specific knowledge of complex structured query languages or XML data schemas, the ambiguity of keyword query may result in generating a great number of results that may be classified into different types. For users, each result type implies a possible search intention. To improve the performance of keyword query, it is desirable to efficiently work out the most relevant result type from the retrieved data. Several recent research works have focused on this interesting problem by using data schema information or pure IR-style statical information. However, this problem is still open due to some requirements. (1) The data to be retrieved may not contain schema information; (2) Relevant result types should be efficiently computed before keyword query evaluation; (3) The correlation between a result type and a keyword query should be measured by analyzing the distribution of relevant values and str...