15,894 research outputs found
To Normalize, or Not to Normalize: The Impact of Normalization on Part-of-Speech Tagging
Does normalization help Part-of-Speech (POS) tagging accuracy on noisy,
non-canonical data? To the best of our knowledge, little is known on the actual
impact of normalization in a real-world scenario, where gold error detection is
not available. We investigate the effect of automatic normalization on POS
tagging of tweets. We also compare normalization to strategies that leverage
large amounts of unlabeled data kept in its raw form. Our results show that
normalization helps, but does not add consistently beyond just word embedding
layer initialization. The latter approach yields a tagging model that is
competitive with a Twitter state-of-the-art tagger.Comment: In WNUT 201
External Lexical Information for Multilingual Part-of-Speech Tagging
Morphosyntactic lexicons and word vector representations have both proven
useful for improving the accuracy of statistical part-of-speech taggers. Here
we compare the performances of four systems on datasets covering 16 languages,
two of these systems being feature-based (MEMMs and CRFs) and two of them being
neural-based (bi-LSTMs). We show that, on average, all four approaches perform
similarly and reach state-of-the-art results. Yet better performances are
obtained with our feature-based models on lexically richer datasets (e.g. for
morphologically rich languages), whereas neural-based results are higher on
datasets with less lexical variability (e.g. for English). These conclusions
hold in particular for the MEMM models relying on our system MElt, which
benefited from newly designed features. This shows that, under certain
conditions, feature-based approaches enriched with morphosyntactic lexicons are
competitive with respect to neural methods
Dictionary writing system (DWS) plus corpus query package (CQP): the case of TshwaneLex
In this article the integrated corpus query functionality of the dictionary compilation software TshwanelLex is analysed. Attention is given to the handling of both raw corpus data and annotated corpus data. With regard to the latter it is shown how, with a minimum of human effort, machine learning techniques can be employed to obtain part-of-speech tagged corpora that can be used for lexicographic purposes. All points are illustrated with data drawn from English and Northern Sotho. The tools and techniques themselves, however, are language-independent, and as Such the encouraging outcomes of this study are far-reaching
Methods for Amharic part-of-speech tagging
The paper describes a set of experiments
involving the application of three state-of-
the-art part-of-speech taggers to Ethiopian
Amharic, using three different tagsets.
The taggers showed worse performance
than previously reported results for Eng-
lish, in particular having problems with
unknown words. The best results were
obtained using a Maximum Entropy ap-
proach, while HMM-based and SVM-
based taggers got comparable results
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