%0 Journal Article %T The effect of using a thesaurus in Arabic information retrieval system %A Mohammad Wedyan %A Basim Alhadidi %A Adnan Alrabea %J International Journal of Computer Science Issues %D 2012 %I IJCSI Press %X Automatic query expansion methods for English and other languages text retrieval have been studied for a long time. In this research we study the retrieval effectiveness, achieved when we apply a successful automatic query expansion method in Arabic text retrieval based on an automatic thesaurus. Our experiments show that the automatic query expansion method resulted in a notable improvement in Arabic text retrieval using a sample of abstracts of Arabic documents. The study showed that the use of a thesaurus has improved information retrieval system by 10% -20%. The study also shows that the greater the number of documents in the building thesaurus, Thesaurus was more accurate. %K Arabic retrieval %K thesaurus %K stop words %K indexing %K information retrieval system %K IJCSI %U http://www.ijcsi.org/papers/IJCSI-9-6-1-431-435.pdf