Enhanced Rules Application Order to Stem Affixation, Reduplication and Compounding Words in Malay Texts

Word stemmer is an automated program to remove affixes, clitics and particles from derived words based on morphological structures of specific natural languages. It has been widely used for text preprocessing in many artificial intelligence applications. Furthermore, the performance of word stemmer to correctly stem derived words has an influence to the performance of information retrieval, text mining and text categorization applications. Despite of various stemming approaches were proposed in the past research, the existing word stemmers for Malay language still suffer from stemming errors. Moreover, the existing word stemmers partially consider morphological structures of Malay language in which only focused on affixation words instead of affixation, reduplication and compounding words, simultaneously. Therefore, this paper proposes an enhanced word stemmer using rule-based affixes removal and dictionary lookup methods called enhanced rule application order that is able to stem affixation, reduplication and compounding words and at the same time, is able to address possible stemming errors. This paper also examines possible root causes of affixation, reduplication and compounding stemming errors that could happen during word stemming process. The experimental results indicate that the proposed word stemmer is able to stem affixation, reduplication and compounding words with better stemming accuracy by using enhanced rule application order.