DCU-Symantec at the WMT 2013 Quality Estimation Shared Task

We describe the two systems submitted by the DCU-Symantec team to Task 1.1. of the WMT 2013 Shared Task on Quality Estimation for Machine Translation. Task 1.1 involve estimating post-editing effort for English-Spanish translation pairs in the news domain. The two systems use a wide variety of features, of which the most effective are the word-alignment, n-gram frequency, language model, POS-tag-based and pseudo-references ones. Both systems perform at a similarly high level in the two tasks of scoring and ranking translations, although there is some evidence that the systems are over-fitting to the training data

DCU: aspect-based polarity classification for SemEval task 4

We describe the work carried out by DCU on the Aspect Based Sentiment Analysis task at SemEval 2014. Our team submitted one constrained run for the restaurant domain and one for the laptop domain for sub-task B (aspect term polarity prediction), ranking highest out of 36 systems on the restaurant test set and joint highest out of 32 systems on the laptop test set

The role of syntax and semantics in machine translation and quality estimation of machine-translated user-generated content

The availability of the Internet has led to a steady increase in the volume of online user-generated content, the majority of which is in English. Machine-translating this content to other languages can help disseminate the information contained in it to a broader audience. However, reliably publishing these translations requires a prior estimate of their quality. This thesis is concerned with the statistical machine translation of Symantec's Norton forum content, focusing in particular on its quality estimation (QE) using syntactic and semantic information. We compare the output of phrase-based and syntax-based English-to-French and English-to-German machine translation (MT) systems automatically and manually, and nd that the syntax-based methods do not necessarily handle grammar-related phenomena in translation better than the phrase-based methods. Although these systems generate suciently dierent outputs, the apparent lack of a systematic dierence between these outputs impedes its utilisation in a combination framework. To investigate the role of syntax and semantics in quality estimation of machine translation, we create SymForum, a data set containing French machine translations of English sentences from Norton forum content, their post-edits and their adequacy and uency scores. We use syntax in quality estimation via tree kernels, hand-crafted features and their combination, and nd it useful both alone and in combination with surface-driven features. Our analyses show that neither the accuracy of the syntactic parses used by these systems nor the parsing quality of the MT output aect QE performance. We also nd that adding more structure to French Treebank parse trees can be useful for syntax-based QE. We use semantic role labelling (SRL) for our semantic-based QE experiments. We experiment with the limited resources that are available for French and nd that a small manually annotated training set is substantially more useful than a much larger articially created set. We use SRL in quality estimation using tree kernels, hand-crafted features and their combination. Additionally, we introduce PAM, a QE metric based on the predicate-argument structure match between source and target. We nd that the SRL quality, especially on the target side, is the major factor negatively aecting the performance of the semantic-based QE. Finally, we annotate English and French Norton forum sentences with their phrase structure syntax using an annotation strategy adapted for user-generated text. We nd that user errors occur in only a small fraction of the data, but their correction does improve parsing performance. These treebanks (Foreebank) prove to be useful as supplementary training data in adapting the parsers to the forum text. The improved parses ultimately increase the performance of the semantic-based QE. However, a reliable semantic-based QE system requires further improvements in the quality of the underlying semantic role labelling

Human Feedback in Statistical Machine Translation

The thesis addresses the challenge of improving Statistical Machine Translation (SMT) systems via feedback given by humans on translation quality. The amount of human feedback available to systems is inherently low due to cost and time limitations. One of our goals is to simulate such information by automatically generating pseudo-human feedback. This is performed using Quality Estimation (QE) models. QE is a technique for predicting the quality of automatic translations without comparing them to oracle (human) translations, traditionally at the sentence or word levels. QE models are trained on a small collection of automatic translations manually labelled for quality, and then can predict the quality of any number of unseen translations. We propose a number of improvements for QE models in order to increase the reliability of pseudo-human feedback. These include strategies to artificially generate instances for settings where QE training data is scarce. We also introduce a new level of granularity for QE: the level of phrases. This level aims to improve the quality of QE predictions by better modelling inter-dependencies among errors at word level, and in ways that are tailored to phrase-based SMT, where the basic unit of translation is a phrase. This can thus facilitate work on incorporating human feedback during the translation process. Finally, we introduce approaches to incorporate pseudo-human feedback in the form of QE predictions in SMT systems. More specifically, we use quality predictions to select the best translation from a number of alternative suggestions produced by SMT systems, and integrate QE predictions into an SMT system decoder in order to guide the translation generation process

Deep interactive text prediction and quality estimation in translation interfaces

The output of automatic translation systems is usually destined for human consumption. In most cases, translators use machine translation (MT) as the first step in the process of creating a fluent translation in a target language given a text in a source language. However, there are many possible ways for translators to interact with MT. The goal of this thesis is to investigate new interactive designs and interfaces for translation. In the first part of the thesis, we present pilot studies which investigate aspects of the interactive translation process, building upon insights from Human-Computer Interaction (HCI) and Translation Studies. We developed HandyCAT, an open-source platform for translation process research, which was used to conduct two user studies: an investigation into interactive machine translation and evaluation of a novel component for post-editing. We then propose new models for quality estimation (QE) of MT, and new models for es- timating the confidence of prefix-based neural interactive MT (IMT) systems. We present a series of experiments using neural sequence models for QE and IMT. We focus upon token-level QE models, which can be used as standalone components or integrated into post-editing pipelines, guiding users in selecting phrases to edit. We introduce a strong recurrent baseline for neural QE, and show how state of the art automatic post-editing (APE) models can be re-purposed for word-level QE. We also propose an auxiliary con- fidence model, which can be attached to (I)-MT systems to use the model’s internal state to estimate confidence about the model’s predictions. The third part of the thesis introduces lexically constrained decoding using grid beam search (GBS), a means of expanding prefix-based interactive translation to general lexical constraints. By integrating lexically constrained decoding with word-level QE, we then suggest a novel interactive design for translation interfaces, and test our hypotheses using simulated editing. The final section focuses upon designing an interface for interactive post-editing, incorporating both GBS and QE. We design components which introduce a new way of interacting with translation models, and test these components in a user-study

Community post-editing of machine-translated user-generated content

With the constant growth of user-generated content (UGC) online, the demand for quick translations of large volumes of texts increases. This is often met with a combination of machine translation (MT) and post-editing (PE). Despite extensive research in post-editing with professional translators or translation students, there are few PE studies with lay post-editors, such as domain experts. This thesis explores lay post-editing as a feasible solution for UGC in a technology support forum, machine translated from English into German. This context of lay post-editing in an online community prompts for a redefinition of quality. We adopt a mixed-methods approach, investigating PE quality quantitatively with an error annotation, a domain specialist evaluation and an end-user evaluation. We further explore post-editing behaviour, i.e. specific edits performed, from a qualitative perspective. With the involvement of community members, the need for a PE competence model becomes even more pressing. We investigate whether Gopferich’s translation competence (TC) model (2009) may serve as a basis for lay post-editing. Our quantitative data proves with statistical significance that lay post-editing is a feasible concept, producing variable output, however. On a qualitative level, post-editing is successful for short segments requiring ~35% post-editing effort. No post-editing patterns were detected for segments requiring more PE effort. Lastly, our data suggests that PE quality is largely independent of the profile characteristics measured. This thesis constitutes an important advance in lay post-editing and benchmarking the evaluation of its output, uncovering difficulties in pinpointing reasons for variance in the resulting quality

Proceedings of the 17th Annual Conference of the European Association for Machine Translation

Proceedings of the 17th Annual Conference of the European Association for Machine Translation (EAMT

On the effective deployment of current machine translation technology

Machine translation is a fundamental technology that is gaining more importance each day in our multilingual society. Companies and particulars are turning their attention to machine translation since it dramatically cuts down their expenses on translation and interpreting. However, the output of current machine translation systems is still far from the quality of translations generated by human experts. The overall goal of this thesis is to narrow down this quality gap by developing new methodologies and tools that improve the broader and more efficient deployment of machine translation technology. We start by proposing a new technique to improve the quality of the translations generated by fully-automatic machine translation systems. The key insight of our approach is that different translation systems, implementing different approaches and technologies, can exhibit different strengths and limitations. Therefore, a proper combination of the outputs of such different systems has the potential to produce translations of improved quality. We present minimum Bayes¿ risk system combination, an automatic approach that detects the best parts of the candidate translations and combines them to generate a consensus translation that is optimal with respect to a particular performance metric. We thoroughly describe the formalization of our approach as a weighted ensemble of probability distributions and provide efficient algorithms to obtain the optimal consensus translation according to the widespread BLEU score. Empirical results show that the proposed approach is indeed able to generate statistically better translations than the provided candidates. Compared to other state-of-the-art systems combination methods, our approach reports similar performance not requiring any additional data but the candidate translations. Then, we focus our attention on how to improve the utility of automatic translations for the end-user of the system. Since automatic translations are not perfect, a desirable feature of machine translation systems is the ability to predict at run-time the quality of the generated translations. Quality estimation is usually addressed as a regression problem where a quality score is predicted from a set of features that represents the translation. However, although the concept of translation quality is intuitively clear, there is no consensus on which are the features that actually account for it. As a consequence, quality estimation systems for machine translation have to utilize a large number of weak features to predict translation quality. This involves several learning problems related to feature collinearity and ambiguity, and due to the ¿curse¿ of dimensionality. We address these challenges by adopting a two-step training methodology. First, a dimensionality reduction method computes, from the original features, the reduced set of features that better explains translation quality. Then, a prediction model is built from this reduced set to finally predict the quality score. We study various reduction methods previously used in the literature and propose two new ones based on statistical multivariate analysis techniques. More specifically, the proposed dimensionality reduction methods are based on partial least squares regression. The results of a thorough experimentation show that the quality estimation systems estimated following the proposed two-step methodology obtain better prediction accuracy that systems estimated using all the original features. Moreover, one of the proposed dimensionality reduction methods obtained the best prediction accuracy with only a fraction of the original features. This feature reduction ratio is important because it implies a dramatic reduction of the operating times of the quality estimation system. An alternative use of current machine translation systems is to embed them within an interactive editing environment where the system and a human expert collaborate to generate error-free translations. This interactive machine translation approach have shown to reduce supervision effort of the user in comparison to the conventional decoupled post-edition approach. However, interactive machine translation considers the translation system as a passive agent in the interaction process. In other words, the system only suggests translations to the user, who then makes the necessary supervision decisions. As a result, the user is bound to exhaustively supervise every suggested translation. This passive approach ensures error-free translations but it also demands a large amount of supervision effort from the user. Finally, we study different techniques to improve the productivity of current interactive machine translation systems. Specifically, we focus on the development of alternative approaches where the system becomes an active agent in the interaction process. We propose two different active approaches. On the one hand, we describe an active interaction approach where the system informs the user about the reliability of the suggested translations. The hope is that this information may help the user to locate translation errors thus improving the overall translation productivity. We propose different scores to measure translation reliability at the word and sentence levels and study the influence of such information in the productivity of an interactive machine translation system. Empirical results show that the proposed active interaction protocol is able to achieve a large reduction in supervision effort while still generating translations of very high quality. On the other hand, we study an active learning framework for interactive machine translation. In this case, the system is not only able to inform the user of which suggested translations should be supervised, but it is also able to learn from the user-supervised translations to improve its future suggestions. We develop a value-of-information criterion to select which automatic translations undergo user supervision. However, given its high computational complexity, in practice we study different selection strategies that approximate this optimal criterion. Results of a large scale experimentation show that the proposed active learning framework is able to obtain better compromises between the quality of the generated translations and the human effort required to obtain them. Moreover, in comparison to a conventional interactive machine translation system, our proposal obtained translations of twice the quality with the same supervision effort.González Rubio, J. (2014). On the effective deployment of current machine translation technology [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/37888TESI

WICC 2017 : XIX Workshop de Investigadores en Ciencias de la Computación

Actas del XIX Workshop de Investigadores en Ciencias de la Computación (WICC 2017), realizado en el Instituto Tecnológico de Buenos Aires (ITBA), el 27 y 28 de abril de 2017.Red de Universidades con Carreras en Informática (RedUNCI