42 research outputs found
Data sparsity in highly inflected languages: the case of morphosyntactic tagging in Polish
In morphologically complex languages, many high-level tasks in natural language
processing rely on accurate morphosyntactic analyses of the input. However, in
light of the risk of error propagation in present-day pipeline architectures for basic
linguistic pre-processing, the state of the art for morphosyntactic tagging is still
not satisfactory. The main obstacle here is data sparsity inherent to natural lan-
guage in general and highly inflected languages in particular.
In this work, we investigate whether semi-supervised systems may alleviate the
data sparsity problem. Our approach uses word clusters obtained from large
amounts of unlabelled text in an unsupervised manner in order to provide a su-
pervised probabilistic tagger with morphologically informed features. Our evalua-
tions on a number of datasets for the Polish language suggest that this simple
technique improves tagging accuracy, especially with regard to out-of-vocabulary
words. This may prove useful to increase cross-domain performance of taggers,
and to alleviate the dependency on large amounts of supervised training data,
which is especially important from the perspective of less-resourced languages
Proceedings of the Seventh International Conference Formal Approaches to South Slavic and Balkan languages
Proceedings of the Seventh International Conference Formal Approaches to South Slavic and Balkan Languages publishes 17 papers that were presented at the conference organised in Dubrovnik, Croatia, 4-6 Octobre 2010
many faces, many places (Term21)
UIDB/03213/2020
UIDP/03213/2020publishersversionpublishe
many faces, many places (Term21)
UIDB/03213/2020
UIDP/03213/2020Proceedings of the LREC 2022 Workshop Language Resources and Evaluation Conferencepublishersversionpublishe
One Model to Rule them all: Multitask and Multilingual Modelling for Lexical Analysis
When learning a new skill, you take advantage of your preexisting skills and
knowledge. For instance, if you are a skilled violinist, you will likely have
an easier time learning to play cello. Similarly, when learning a new language
you take advantage of the languages you already speak. For instance, if your
native language is Norwegian and you decide to learn Dutch, the lexical overlap
between these two languages will likely benefit your rate of language
acquisition. This thesis deals with the intersection of learning multiple tasks
and learning multiple languages in the context of Natural Language Processing
(NLP), which can be defined as the study of computational processing of human
language. Although these two types of learning may seem different on the
surface, we will see that they share many similarities.
The traditional approach in NLP is to consider a single task for a single
language at a time. However, recent advances allow for broadening this
approach, by considering data for multiple tasks and languages simultaneously.
This is an important approach to explore further as the key to improving the
reliability of NLP, especially for low-resource languages, is to take advantage
of all relevant data whenever possible. In doing so, the hope is that in the
long term, low-resource languages can benefit from the advances made in NLP
which are currently to a large extent reserved for high-resource languages.
This, in turn, may then have positive consequences for, e.g., language
preservation, as speakers of minority languages will have a lower degree of
pressure to using high-resource languages. In the short term, answering the
specific research questions posed should be of use to NLP researchers working
towards the same goal.Comment: PhD thesis, University of Groninge
A Computational Lexicon and Representational Model for Arabic Multiword Expressions
The phenomenon of multiword expressions (MWEs) is increasingly recognised as a serious and challenging issue that has attracted the attention of researchers in various language-related disciplines. Research in these many areas has emphasised the primary role of MWEs in the process of analysing and understanding language, particularly in the computational treatment of natural languages. Ignoring MWE knowledge in any NLP system reduces the possibility of achieving high precision outputs. However, despite the enormous wealth of MWE research and language resources available for English and some other languages, research on Arabic MWEs (AMWEs) still faces multiple challenges, particularly in key computational tasks such as extraction, identification, evaluation, language resource building, and lexical representations.
This research aims to remedy this deficiency by extending knowledge of AMWEs and making noteworthy contributions to the existing literature in three related research areas on the way towards building a computational lexicon of AMWEs. First, this study develops a general understanding of AMWEs by establishing a detailed conceptual framework that includes a description of an adopted AMWE concept and its distinctive properties at multiple linguistic levels. Second, in the use of AMWE extraction and discovery tasks, the study employs a hybrid approach that combines knowledge-based and data-driven computational methods for discovering multiple types of AMWEs. Third, this thesis presents a representative system for AMWEs which consists of multilayer encoding of extensive linguistic descriptions.
This project also paves the way for further in-depth AMWE-aware studies in NLP and linguistics to gain new insights into this complicated phenomenon in standard Arabic. The implications of this research are related to the vital role of the AMWE lexicon, as a new lexical resource, in the improvement of various ANLP tasks and the potential opportunities this lexicon provides for linguists to analyse and explore AMWE phenomena