MoNoise: Modeling Noise Using a Modular Normalization System

We propose MoNoise: a normalization model focused on generalizability and efficiency, it aims at being easily reusable and adaptable. Normalization is the task of translating texts from a non- canonical domain to a more canonical domain, in our case: from social media data to standard language. Our proposed model is based on a modular candidate generation in which each module is responsible for a different type of normalization action. The most important generation modules are a spelling correction system and a word embeddings module. Depending on the definition of the normalization task, a static lookup list can be crucial for performance. We train a random forest classifier to rank the candidates, which generalizes well to all different types of normaliza- tion actions. Most features for the ranking originate from the generation modules; besides these features, N-gram features prove to be an important source of information. We show that MoNoise beats the state-of-the-art on different normalization benchmarks for English and Dutch, which all define the task of normalization slightly different.Comment: Source code: https://bitbucket.org/robvanderg/monois

Adapting Sequence to Sequence models for Text Normalization in Social Media

Social media offer an abundant source of valuable raw data, however informal writing can quickly become a bottleneck for many natural language processing (NLP) tasks. Off-the-shelf tools are usually trained on formal text and cannot explicitly handle noise found in short online posts. Moreover, the variety of frequently occurring linguistic variations presents several challenges, even for humans who might not be able to comprehend the meaning of such posts, especially when they contain slang and abbreviations. Text Normalization aims to transform online user-generated text to a canonical form. Current text normalization systems rely on string or phonetic similarity and classification models that work on a local fashion. We argue that processing contextual information is crucial for this task and introduce a social media text normalization hybrid word-character attention-based encoder-decoder model that can serve as a pre-processing step for NLP applications to adapt to noisy text in social media. Our character-based component is trained on synthetic adversarial examples that are designed to capture errors commonly found in online user-generated text. Experiments show that our model surpasses neural architectures designed for text normalization and achieves comparable performance with state-of-the-art related work.Comment: Accepted at the 13th International AAAI Conference on Web and Social Media (ICWSM 2019

A Taxonomy for In-depth Evaluation of Normalization for User Generated Content

In this work we present a taxonomy of error categories for lexical normalization, which is the task of translating user generated content to canonical language. We annotate a recent normalization dataset to test the practical use of the taxonomy and read a near-perfect agreement. This annotated dataset is then used to evaluate how an existing normalization model performs on the different categories of the taxonomy. The results of this evaluation reveal that some of the problematic categories only include minor transformations, whereas most regular transformations are solved quite well

Neural text normalization for Turkish social media

This is an accepted manuscript of an article published by IEEE in 2018 3rd International Conference on Computer Science and Engineering (UBMK) on 10/12/2018, available online: https://ieeexplore.ieee.org/document/8566406 The accepted version of the publication may differ from the final published version.Social media has become a rich data source for natural language processing tasks with its worldwide use; however, it is hard to process social media data due to its informal nature. Text normalization is the task of transforming the noisy text into its canonical form. It generally serves as a preprocessing task in other NLP tasks that are applied to noisy text. In this study, we apply two approaches for Turkish text normalization: Contextual Normalization approach using distributed representations of words and Sequence-to-Sequence Normalization approach using neural encoder-decoder models. As the approaches applied to Turkish and also other languages are mostly rule-based, additional rules are required to be added to the normalization model in order to detect new error patterns arising from the change of the language use in social media. In contrast to rule-based approaches, the proposed approaches provide the advantage of normalizing different error patterns that change over time by training with a new dataset and updating the normalization model. Therefore, the proposed methods provide a solution to language change dependency in social media by updating the normalization model without defining new rules.Published versio

Enhancing BERT for Lexical Normalization

International audienceLanguage model-based pre-trained representations have become ubiquitous in natural language processing. They have been shown to significantly improve the performance of neu-ral models on a great variety of tasks. However , it remains unclear how useful those general models can be in handling non-canonical text. In this article, focusing on User Generated Content (UGC) in a resource-scarce scenario , we study the ability of BERT (Devlin et al., 2018) to perform lexical normalisation. Our contribution is simple: by framing lexical normalisation as a token prediction task, by enhancing its architecture and by carefully fine-tuning it, we show that BERT can be a competitive lexical normalisation model without the need of any UGC resources aside from 3,000 training sentences. To the best of our knowledge , it is the first work done in adapting and analysing the ability of this model to handle noisy UGC data