Siegfried Handschuh


2022

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Shallow Discourse Parsing for Open Information Extraction and Text Simplification
Christina Niklaus | André Freitas | Siegfried Handschuh
Proceedings of the 3rd Workshop on Computational Approaches to Discourse

We present a discourse-aware text simplification (TS) approach that recursively splits and rephrases complex English sentences into a semantic hierarchy of simplified sentences. Using a set of linguistically principled transformation patterns, sentences are converted into a hierarchical representation in the form of core sentences and accompanying contexts that are linked via rhetorical relations. As opposed to previously proposed sentence splitting approaches, which commonly do not take into account discourse-level aspects, our TS approach preserves the semantic relationship of the decomposed constituents in the output. A comparative analysis with the annotations contained in RST-DT shows that we capture the contextual hierarchy between the split sentences with a precision of 89% and reach an average precision of 69% for the classification of the rhetorical relations that hold between them. Moreover, an integration into state-of-the-art Open Information Extraction (IE) systems reveals that when applying our TS approach as a pre-processing step, the generated relational tuples are enriched with additional meta information, resulting in a novel lightweight semantic representation for the task of Open IE.

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A Philosophically-Informed Contribution to the Generalization Problem of Neural Natural Language Inference: Shallow Heuristics, Bias, and the Varieties of Inference
Reto Gubelmann | Christina Niklaus | Siegfried Handschuh
Proceedings of the 3rd Natural Logic Meets Machine Learning Workshop (NALOMA III)

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Context Matters: A Pragmatic Study of PLMs’ Negation Understanding
Reto Gubelmann | Siegfried Handschuh
Proceedings of the 60th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)

In linguistics, there are two main perspectives on negation: a semantic and a pragmatic view. So far, research in NLP on negation has almost exclusively adhered to the semantic view. In this article, we adopt the pragmatic paradigm to conduct a study of negation understanding focusing on transformer-based PLMs. Our results differ from previous, semantics-based studies and therefore help to contribute a more comprehensive – and, given the results, much more optimistic – picture of the PLMs’ negation understanding.

2021

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Supporting Cognitive and Emotional Empathic Writing of Students
Thiemo Wambsganss | Christina Niklaus | Matthias Söllner | Siegfried Handschuh | Jan Marco Leimeister
Proceedings of the 59th Annual Meeting of the Association for Computational Linguistics and the 11th International Joint Conference on Natural Language Processing (Volume 1: Long Papers)

We present an annotation approach to capturing emotional and cognitive empathy in student-written peer reviews on business models in German. We propose an annotation scheme that allows us to model emotional and cognitive empathy scores based on three types of review components. Also, we conducted an annotation study with three annotators based on 92 student essays to evaluate our annotation scheme. The obtained inter-rater agreement of α=0.79 for the components and the multi-π=0.41 for the empathy scores indicate that the proposed annotation scheme successfully guides annotators to a substantial to moderate agreement. Moreover, we trained predictive models to detect the annotated empathy structures and embedded them in an adaptive writing support system for students to receive individual empathy feedback independent of an instructor, time, and location. We evaluated our tool in a peer learning exercise with 58 students and found promising results for perceived empathy skill learning, perceived feedback accuracy, and intention to use. Finally, we present our freely available corpus of 500 empathy-annotated, student-written peer reviews on business models and our annotation guidelines to encourage future research on the design and development of empathy support systems.

2020

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A Corpus for Argumentative Writing Support in German
Thiemo Wambsganss | Christina Niklaus | Matthias Söllner | Siegfried Handschuh | Jan Marco Leimeister
Proceedings of the 28th International Conference on Computational Linguistics

In this paper, we present a novel annotation approach to capture claims and premises of arguments and their relations in student-written persuasive peer reviews on business models in German language. We propose an annotation scheme based on annotation guidelines that allows to model claims and premises as well as support and attack relations for capturing the structure of argumentative discourse in student-written peer reviews. We conduct an annotation study with three annotators on 50 persuasive essays to evaluate our annotation scheme. The obtained inter-rater agreement of α = 0.57 for argument components and α = 0.49 for argumentative relations indicates that the proposed annotation scheme successfully guides annotators to moderate agreement. Finally, we present our freely available corpus of 1,000 persuasive student-written peer reviews on business models and our annotation guidelines to encourage future research on the design and development of argumentative writing support systems for students.

2019

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MinWikiSplit: A Sentence Splitting Corpus with Minimal Propositions
Christina Niklaus | André Freitas | Siegfried Handschuh
Proceedings of the 12th International Conference on Natural Language Generation

We compiled a new sentence splitting corpus that is composed of 203K pairs of aligned complex source and simplified target sentences. Contrary to previously proposed text simplification corpora, which contain only a small number of split examples, we present a dataset where each input sentence is broken down into a set of minimal propositions, i.e. a sequence of sound, self-contained utterances with each of them presenting a minimal semantic unit that cannot be further decomposed into meaningful propositions. This corpus is useful for developing sentence splitting approaches that learn how to transform sentences with a complex linguistic structure into a fine-grained representation of short sentences that present a simple and more regular structure which is easier to process for downstream applications and thus facilitates and improves their performance.

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DisSim: A Discourse-Aware Syntactic Text Simplification Framework for English and German
Christina Niklaus | Matthias Cetto | André Freitas | Siegfried Handschuh
Proceedings of the 12th International Conference on Natural Language Generation

We introduce DisSim, a discourse-aware sentence splitting framework for English and German whose goal is to transform syntactically complex sentences into an intermediate representation that presents a simple and more regular structure which is easier to process for downstream semantic applications. For this purpose, we turn input sentences into a two-layered semantic hierarchy in the form of core facts and accompanying contexts, while identifying the rhetorical relations that hold between them. In that way, we preserve the coherence structure of the input and, hence, its interpretability for downstream tasks.

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Transforming Complex Sentences into a Semantic Hierarchy
Christina Niklaus | Matthias Cetto | André Freitas | Siegfried Handschuh
Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics

We present an approach for recursively splitting and rephrasing complex English sentences into a novel semantic hierarchy of simplified sentences, with each of them presenting a more regular structure that may facilitate a wide variety of artificial intelligence tasks, such as machine translation (MT) or information extraction (IE). Using a set of hand-crafted transformation rules, input sentences are recursively transformed into a two-layered hierarchical representation in the form of core sentences and accompanying contexts that are linked via rhetorical relations. In this way, the semantic relationship of the decomposed constituents is preserved in the output, maintaining its interpretability for downstream applications. Both a thorough manual analysis and automatic evaluation across three datasets from two different domains demonstrate that the proposed syntactic simplification approach outperforms the state of the art in structural text simplification. Moreover, an extrinsic evaluation shows that when applying our framework as a preprocessing step the performance of state-of-the-art Open IE systems can be improved by up to 346% in precision and 52% in recall. To enable reproducible research, all code is provided online.

2018

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Indra: A Word Embedding and Semantic Relatedness Server
Juliano Efson Sales | Leonardo Souza | Siamak Barzegar | Brian Davis | André Freitas | Siegfried Handschuh
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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A Multilingual Test Collection for the Semantic Search of Entity Categories
Juliano Efson Sales | Siamak Barzegar | Wellington Franco | Bernhard Bermeitinger | Tiago Cunha | Brian Davis | André Freitas | Siegfried Handschuh
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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Building a Knowledge Graph from Natural Language Definitions for Interpretable Text Entailment Recognition
Vivian Silva | André Freitas | Siegfried Handschuh
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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SemR-11: A Multi-Lingual Gold-Standard for Semantic Similarity and Relatedness for Eleven Languages
Siamak Barzegar | Brian Davis | Manel Zarrouk | Siegfried Handschuh | Andre Freitas
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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Graphene: Semantically-Linked Propositions in Open Information Extraction
Matthias Cetto | Christina Niklaus | André Freitas | Siegfried Handschuh
Proceedings of the 27th International Conference on Computational Linguistics

We present an Open Information Extraction (IE) approach that uses a two-layered transformation stage consisting of a clausal disembedding layer and a phrasal disembedding layer, together with rhetorical relation identification. In that way, we convert sentences that present a complex linguistic structure into simplified, syntactically sound sentences, from which we can extract propositions that are represented in a two-layered hierarchy in the form of core relational tuples and accompanying contextual information which are semantically linked via rhetorical relations. In a comparative evaluation, we demonstrate that our reference implementation Graphene outperforms state-of-the-art Open IE systems in the construction of correct n-ary predicate-argument structures. Moreover, we show that existing Open IE approaches can benefit from the transformation process of our framework.

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A Survey on Open Information Extraction
Christina Niklaus | Matthias Cetto | André Freitas | Siegfried Handschuh
Proceedings of the 27th International Conference on Computational Linguistics

We provide a detailed overview of the various approaches that were proposed to date to solve the task of Open Information Extraction. We present the major challenges that such systems face, show the evolution of the suggested approaches over time and depict the specific issues they address. In addition, we provide a critique of the commonly applied evaluation procedures for assessing the performance of Open IE systems and highlight some directions for future work.

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Graphene: a Context-Preserving Open Information Extraction System
Matthias Cetto | Christina Niklaus | André Freitas | Siegfried Handschuh
Proceedings of the 27th International Conference on Computational Linguistics: System Demonstrations

We introduce Graphene, an Open IE system whose goal is to generate accurate, meaningful and complete propositions that may facilitate a variety of downstream semantic applications. For this purpose, we transform syntactically complex input sentences into clean, compact structures in the form of core facts and accompanying contexts, while identifying the rhetorical relations that hold between them in order to maintain their semantic relationship. In that way, we preserve the context of the relational tuples extracted from a source sentence, generating a novel lightweight semantic representation for Open IE that enhances the expressiveness of the extracted propositions.

2017

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SemEval-2017 Task 5: Fine-Grained Sentiment Analysis on Financial Microblogs and News
Keith Cortis | André Freitas | Tobias Daudert | Manuela Huerlimann | Manel Zarrouk | Siegfried Handschuh | Brian Davis
Proceedings of the 11th International Workshop on Semantic Evaluation (SemEval-2017)

This paper discusses the “Fine-Grained Sentiment Analysis on Financial Microblogs and News” task as part of SemEval-2017, specifically under the “Detecting sentiment, humour, and truth” theme. This task contains two tracks, where the first one concerns Microblog messages and the second one covers News Statements and Headlines. The main goal behind both tracks was to predict the sentiment score for each of the mentioned companies/stocks. The sentiment scores for each text instance adopted floating point values in the range of -1 (very negative/bearish) to 1 (very positive/bullish), with 0 designating neutral sentiment. This task attracted a total of 32 participants, with 25 participating in Track 1 and 29 in Track 2.

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SemEval-2017 Task 11: End-User Development using Natural Language
Juliano Sales | Siegfried Handschuh | André Freitas
Proceedings of the 11th International Workshop on Semantic Evaluation (SemEval-2017)

This task proposes a challenge to support the interaction between users and applications, micro-services and software APIs using natural language. The task aims for supporting the evaluation and evolution of the discussions surrounding the natural language processing approaches within the context of end-user natural language programming, under scenarios of high semantic heterogeneity/gap.

2016

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A Sentence Simplification System for Improving Relation Extraction
Christina Niklaus | Bernhard Bermeitinger | Siegfried Handschuh | André Freitas
Proceedings of COLING 2016, the 26th International Conference on Computational Linguistics: System Demonstrations

We present a text simplification approach that is directed at improving the performance of state-of-the-art Open Relation Extraction (RE) systems. As syntactically complex sentences often pose a challenge for current Open RE approaches, we have developed a simplification framework that performs a pre-processing step by taking a single sentence as input and using a set of syntactic-based transformation rules to create a textual input that is easier to process for subsequently applied Open RE systems.

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NNBlocks: A Deep Learning Framework for Computational Linguistics Neural Network Models
Frederico Tommasi Caroli | André Freitas | João Carlos Pereira da Silva | Siegfried Handschuh
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

Lately, with the success of Deep Learning techniques in some computational linguistics tasks, many researchers want to explore new models for their linguistics applications. These models tend to be very different from what standard Neural Networks look like, limiting the possibility to use standard Neural Networks frameworks. This work presents NNBlocks, a new framework written in Python to build and train Neural Networks that are not constrained by a specific kind of architecture, making it possible to use it in computational linguistics.

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Semantic Relation Classification: Task Formalisation and Refinement
Vivian Santos | Manuela Huerliman | Brian Davis | Siegfried Handschuh | André Freitas
Proceedings of the 5th Workshop on Cognitive Aspects of the Lexicon (CogALex - V)

The identification of semantic relations between terms within texts is a fundamental task in Natural Language Processing which can support applications requiring a lightweight semantic interpretation model. Currently, semantic relation classification concentrates on relations which are evaluated over open-domain data. This work provides a critique on the set of abstract relations used for semantic relation classification with regard to their ability to express relationships between terms which are found in a domain-specific corpora. Based on this analysis, this work proposes an alternative semantic relation model based on reusing and extending the set of abstract relations present in the DOLCE ontology. The resulting set of relations is well grounded, allows to capture a wide range of relations and could thus be used as a foundation for automatic classification of semantic relations.

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Categorization of Semantic Roles for Dictionary Definitions
Vivian Silva | Siegfried Handschuh | André Freitas
Proceedings of the 5th Workshop on Cognitive Aspects of the Lexicon (CogALex - V)

Understanding the semantic relationships between terms is a fundamental task in natural language processing applications. While structured resources that can express those relationships in a formal way, such as ontologies, are still scarce, a large number of linguistic resources gathering dictionary definitions is becoming available, but understanding the semantic structure of natural language definitions is fundamental to make them useful in semantic interpretation tasks. Based on an analysis of a subset of WordNet’s glosses, we propose a set of semantic roles that compose the semantic structure of a dictionary definition, and show how they are related to the definition’s syntactic configuration, identifying patterns that can be used in the development of information extraction frameworks and semantic models.

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A Compositional-Distributional Semantic Model for Searching Complex Entity Categories
Juliano Efson Sales | André Freitas | Brian Davis | Siegfried Handschuh
Proceedings of the Fifth Joint Conference on Lexical and Computational Semantics

2015

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How hard is this query? Measuring the Semantic Complexity of Schema-agnostic Queries
André Freitas | Juliano Efson Sales | Siegfried Handschuh | Edward Curry
Proceedings of the 11th International Conference on Computational Semantics

2014

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Random Manhattan Integer Indexing: Incremental L1 Normed Vector Space Construction
Behrang Q. Zadeh | Siegfried Handschuh
Proceedings of the 2014 Conference on Empirical Methods in Natural Language Processing (EMNLP)

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Evaluation of Technology Term Recognition with Random Indexing
Behrang Zadeh | Siegfried Handschuh
Proceedings of the Ninth International Conference on Language Resources and Evaluation (LREC'14)

In this paper, we propose a method that combines the principles of automatic term recognition and the distributional hypothesis to identify technology terms from a corpus of scientific publications. We employ the random indexing technique to model terms’ surrounding words, which we call the context window, in a vector space at reduced dimension. The constructed vector space and a set of reference vectors, which represents manually annotated technology terms, in a k-nearest-neighbour voting classification scheme are used for term classification. In this paper, we examine a number of parameters that influence the obtained results. First, we inspect several context configurations, i.e. the effect of the context window size, the direction in which co-occurrence counts are collected, and information about the order of words within the context windows. Second, in the k-nearest-neighbour voting scheme, we study the role that neighbourhood size selection plays, i.e. the value of k. The obtained results are similar to word space models. The performed experiments suggest the best performing context are small (i.e. not wider than 3 words), are extended in both directions and encode the word order information. Moreover, the accomplished experiments suggest that the obtained results, to a great extent, are independent of the value of k.

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The ACL RD-TEC: A Dataset for Benchmarking Terminology Extraction and Classification in Computational Linguistics
Behrang Q. Zadeh | Siegfried Handschuh
Proceedings of the 4th International Workshop on Computational Terminology (Computerm)

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Investigating Context Parameters in Technology Term Recognition
Behrang Q. Zadeh | Siegfried Handschuh
Proceedings of the COLING Workshop on Synchronic and Diachronic Approaches to Analyzing Technical Language

2010

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Classifying Action Items for Semantic Email
Simon Scerri | Gerhard Gossen | Brian Davis | Siegfried Handschuh
Proceedings of the Seventh International Conference on Language Resources and Evaluation (LREC'10)

Email can be considered as a virtual working environment in which users are constantly struggling to manage the vast amount of exchanged data. Although most of this data belongs to well-defined workflows, these are implicit and largely unsupported by existing email clients. Semanta provides this support by enabling Semantic Email ― email enhanced with machine-processable metadata about specific types of email Action Items (e.g. Task Assignment, Meeting Proposal). In the larger picture, these items form part of ad-hoc workflows (e.g. Task Delegation, Meeting Scheduling). Semanta is faced with a knowledge-acquisition bottleneck, as users cannot be expected to annotate each action item, and their automatic recognition proves difficult. This paper focuses on applying computationally treatable aspects of speech act theory for the classification of email action items. A rule-based classification model is employed, based on the presence or form of a number of linguistic features. The technology’s evaluation suggests that whereas full automation is not feasible, the results are good enough to be presented as suggestions for the user to review. In addition the rule-based system will bootstrap a machine learning system that is currently in development, to generate the initial training sets which are then improved through the user’s reviewing.

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A Use Case for Controlled Languages as Interfaces to Semantic Web Applications
Pradeep Dantuluri | Brian Davis | Siegfried Handschuh
Proceedings of the Seventh International Conference on Language Resources and Evaluation (LREC'10)

Although the Semantic web is steadily gaining in popularity, it remains a mystery to a large percentage of Internet users. This can be attributed to the complexity of the technologies that form its core. Creating intuitive interfaces which completely abstract the technologies underneath, is one way to solve this problem. A contrasting approach is to ease the user into understanding the technologies. We propose a solution which anchors on using controlled languages as interfaces to semantic web applications. This paper describes one such approach for the domain of meeting minutes, status reports and other project specific documents. A controlled language is developed along with an ontology to handle semi-automatic knowledge extraction. The contributions of this paper include an ontology designed for the domain of meeting minutes and status reports, and a controlled language grammar tailored for the above domain to perform the semi-automatic knowledge acquisition and generate RDF triples. This paper also describes two grammar prototypes, which were developed and evaluated prior to the development of the final grammar, as well as the Link grammar, which was the grammar formalism of choice.

2008

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Evaluating the Ontology underlying sMail - the Conceptual Framework for Semantic Email Communication
Simon Scerri | Myriam Mencke | Brian Davis | Siegfried Handschuh
Proceedings of the Sixth International Conference on Language Resources and Evaluation (LREC'08)

The lack of structure in the content of email messages makes it very hard for data channelled between the sender and the recipient to be correctly interpreted and acted upon. As a result, the purposes of messages frequently end up not being fulfilled, prompting prolonged communication and stalling the disconnected workflow that is characteristic of email. This problem could be partially solved by extending the current email model to support light-weight semantics pertaining to the intents of the sender and the expectations from the recipient(s), thus leaving no room for ambiguity. Semantically-aware email clients will then be able to support the user with the workflow of email-generated tasks. In line with this thinking, we present the sMail Conceptual Framework. At its core, this framework has an Email Speech Act Model. Given this model, email content can be categorized into a set of speech acts, each carrying specific expectations. In this paper we present and discuss the methodology and results of this model?s statistical evaluation. By performing the same evaluation on another existing model, we demonstrate our model?s higher sophistication. After careful observations, we perform changes to the model and subsequently accommodate the changes in the revised sMail Conceptual Framework.

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Linguistically Light Lexical Extensions for Ontologies
Brian Davis | Siegfried Handschuh | Alexander Troussov | John Judge | Mikhail Sogrin
Proceedings of the Sixth International Conference on Language Resources and Evaluation (LREC'08)

The identification of class instances within unstructured text for either the purposes of Ontology population or semantic annotation are usually limited to term mentions of Proper Noun and Personal Noun or fixed Key Phrases within Text Analytics or Ontology based Information Extraction(OBIE) applications. These systems do not generalize to cope with compound nominal classes of multi word expressions. Computational Linguistics’ approaches involving deep analysis tend to suffer from idiomaticity and overgeneration problems while the shallower “words with spaces” approach frequently employed in Information Extraction(IE) and Industrial Text Analytics systems lacks flexibility and is prone to lexical proliferation. We outline a representation for encoding light linguistic features of Compound Nominal term mentions of Concepts within an Ontology as well as a lightweight semantic annotator which complies the above linguistic information into efficient Dictionary formats to drive large scale identification and semantic annotation of the aforementioned concepts.

2003

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Ontology-based Linguistic Annotation
Philipp Cimiano | Siegfried Handschuh
Proceedings of the ACL 2003 Workshop on Linguistic Annotation: Getting the Model Right