Word Stemming for Arabic Information Retrieval: The Case for Simple Light Stemming

Although a number of attempts have been made to develop a stemming formalism for the Arabic language, most of these attempts have focused merely on the lexical structure of words as modeled by the Arabic grammatical and morphological lexical rules. This paper discusses the merits of light stemming for Arabic data and presents a simple light stemming strategy that has been developed on the basis of an analysis of actual occurrence of suffixes and prefixes in real texts. The performance of this stemming strategy has been compared with that of a heavier stemming strategy that takes into consideration most grammatical prefixes and suffixes. The results indicate that only a few of the prefixes and suffixes have an impact on the correctness of stems generated. Light stemming has exhibited superior performance than heavy stemming in terms of over-stemming and under-stemming measures. It has been shown that the two stemming strategies are significantly different in retrieval performance.