Adapting Morphology for Arabic Information Retrieval *

This chapter presents an adaptation of existing techniques in Arabic morphology by leveraging corpus statistics to make them suitable for Information Retrieval (IR). The adaptation resulted in the development of Sebawai, an shallow Arabic morphological analyzer, and Al-Stem, an Arabic light stemmer. Both were used to produce Arabic index terms for Arabic experimentation. Sebawai is concerned with generating possible roots and stems of a given Arabic word along with probability estimates of deriving the word from each of the possible roots. The probability estimates were used as a guide to determine which prefixes and suffixes should be used to build the light stemmer Al-Stem. The use of the Sebawai generated roots and stems as index terms along with the stems from Al-Stem are evaluated in an information retrieval application and the results are compared