Abstract
The effective handling of previously unseen words is an important factor in the performance of part-of-speech taggers. Some trainable POS taggers use suffix (sometimes prefix) strings as cues in handling unknown words (in effect serving as a proxy for actual linguistic affixes). In the context of creating a tagger for the African language Igbo, we compare the performance of some existing taggers, implementing such an approach, to a novel method for handling morphologically complex unknown words, based on morphological reconstruction (i.e. a linguistically-informed segmentation into root and affixes). The novel method outperforms these other systems by several percentage points, achieving accuracies of around 92 % on morphologically-complex unknown words.
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Notes
- 1.
Obtained from jw.org.
- 2.
“Mmadụ Ka A Na-Arịa” written in 2013.
- 3.
Here, “rV” means letter r and any vowel (a,e,u,o,i,ị,ọ,ụ) attached to a word in Igbo like “bịara” came, “kọrọ” told, “riri” ate, “nwuru” shone, etc. It is a past tense marker if attached to active verb or indicate stative/passive meaning if attached to a stative verb [3]. Therefore, it is an important cue in predicting past tense verbs or verbs having applicative meaning “APP”.
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Acknowledgments
We acknowledge the financial support of Tertiary Education Trust Fund Nigeria and Nnamdi Azikiwe University (NAU) Nigeria. Many thanks to Dr. Uchechukwu Chinedu of linguistic department, NAU for his very helpful discussion.
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Onyenwe, I.E., Hepple, M. (2016). Predicting Morphologically-Complex Unknown Words in Igbo. In: Sojka, P., Horák, A., Kopeček, I., Pala, K. (eds) Text, Speech, and Dialogue. TSD 2016. Lecture Notes in Computer Science(), vol 9924. Springer, Cham. https://doi.org/10.1007/978-3-319-45510-5_24
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DOI: https://doi.org/10.1007/978-3-319-45510-5_24
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