Ontology-Driven Query Expansion Using Map/Reduce Framework to Facilitate Federated Queries

In view of the need for a highly distributed and federated architecture, a robust query expansion has great impact on the performance of information retrieval. We aim to determine ontology-driven query expansion terms using different weighting techniques. For this, we consider each individual ontology and user query keywords to determine the Basic Expansion Terms (BET) using a number of semantic measures including Betweenness Measure (BM) and Semantic Similarity Measure (SSM). We propose a Map/Reduce distributed algorithm for calculating all the shortest paths in ontology graph. Map/Reduce algorithm will improve considerably the efficiency of BET calculation for large ontologies.