N-GRAM BASED QUERY STRUCTURING SYSTEM FOR EFFECTIVE XML RETRIEVAL

Query structuring systems are keyword search systems recently used for the effective retrieval of XML documents. Existing systems fail to put keyword query ambiguity prob-lems into consideration during query pre-processing and return irrelevant predicate nodes. As a result, these sys-tems return irrelevant results. In this research, an XML keyword search system, called N-gram based XML query structuring system (NBXQSS) is developed to improve the performance of keyword searches. The NBXQSS uses an N-gram Based Query Segmentation (NBQS) method which interprets a user query as a list of semantic units to help resolve ambiguity. The system also introduces an improved predicate identification algorithm (IPIA) to return rele-vant predicates. The IPIA uses a proposed function to com-pute the query term proximity and ordering. The effective-ness of the NBXQS is demonstrated through experimental performance study on some real-world XML documents. The results show that the developed system performs bet-ter compared to the existing system in terms of precision.