Query reformulation using ontology and keyword for durian web search

Query reformulation techniques based on ontological approach have been studied as a method to improve retrieval effectiveness. However, the evaluation of this techniques has primarily focused on comparing the technique with ontology and without ontology. The aim of this paper is to present, evaluate and compare the proposed technique in four different possibilities of reformulation. In this study we propose the combination of ontology terms and keywords from the query to reformulate new queries. The experimental result shows that reformulation using ontology terms alone has increases recall and decreases precision. However, better results were obtained when the ontology terms being combined with the query's keywords.