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A survey of diacritic restoration in abjad and alphabet writing systems

Published online by Cambridge University Press:  20 November 2017

FRANKLIN ỌLÁDIÍPỌ̀ ASAHIAH ,
ỌDẸ́TÚNJÍ ÀJÀDÍ ỌDẸ́JỌBÍ  and
EMMANUEL RÓTÌMÍ ADÁGÚNODÒ
FRANKLIN ỌLÁDIÍPỌ̀ ASAHIAH
Affiliation:
Department of Computer Science and Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria e-mails: sobusola@oauife.edu.ng, oodejobi@oauife.edu.ng, eadagun@oauife.edu.ng
ỌDẸ́TÚNJÍ ÀJÀDÍ ỌDẸ́JỌBÍ
Affiliation:
Department of Computer Science and Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria e-mails: sobusola@oauife.edu.ng, oodejobi@oauife.edu.ng, eadagun@oauife.edu.ng
EMMANUEL RÓTÌMÍ ADÁGÚNODÒ
Affiliation:
Department of Computer Science and Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria e-mails: sobusola@oauife.edu.ng, oodejobi@oauife.edu.ng, eadagun@oauife.edu.ng
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Abstract

A diacritic is a mark placed near or through a character to alter its original phonetic or orthographic value. Many languages around the world use diacritics in their orthography, whatever the writing system the orthography is based on. In many languages, diacritics are ignored either by convention or as a matter of convenience. For users who are not familiar with the text domain, the absence of diacritics within text has been known to cause mild to serious readability and comprehension problems. However, the absence of diacritics in text causes near-intractable problems for natural language processing systems. This situation has led to extensive research on diacritization. Several techniques have been applied to address diacritic restoration (or diacritization) but the existing surveys of techniques have been restricted to some languages and hence left gaps for practitioners to fill. Our survey examined diacritization from the angle of resources deployed and various formulation employed for diacritization. It was concluded by recommending that (a) any proposed technique for diacritization should consider the language features and the purpose served by diacritics, (b) that evaluation metrics needed to be more rigorously defined for easy comparison of performance of models.

Type
Survey Paper
Information
Natural Language Engineering , Volume 24 , Issue 1 , January 2018 , pp. 123 - 154
Copyright
Copyright © Cambridge University Press 2017 

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