NANYANG TECHNOLOGICAL UNIVERSITY SCHOOL OF HUMANITIES AND SOCIAL SCIENCES Creating derivational morphology links in Wordnet Bahasa

Derivational morphology links are created for the Wordnet Bahasa, a combined Indonesian and Malay online lexical dictionary (Nurril Hirfana, Suerya, & Bond, 2011). The focus was to link root words to affixed words as affixation is one of the more apparent word formation processes in Bahasa Melayu. MorphInd, an Indonesian morphological analyser (Larasati, Kubon, & Zeman, 2011), is used to breakdown affixed words into their root form and affixes. Using Python 2.7 with NLTK, a raw mapping is done by matching the analysed words to the root forms. The derivational links in the Princeton Wordnet (PWN) are used to verify if the same links exist in Wordnet Bahasa. Redundant links are removed by the Part-of-Speech (POS) filter and Semantic Super Type filter. The links are then disambiguated using the Lesk algorithm, where the definitions and other components of the sense (e.g. hypernyms, hyponyms and examples) are compared for their similarity. However, the disambiguation process is rendered ineffective because of the high amount of errors still existing in Wordnet Bahasa. The derivational links are released as a separate file and only those with similar derivational links to PWN are added into Wordnet Bahasa. Erroneous entries that were identified using MorphInd are removed from Wordnet Bahasa.