Thomas Eckart


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Crawling Under-Resourced Languages - a Portal for Community-Contributed Corpus Collection
Erik Körner | Felix Helfer | Christopher Schröder | Thomas Eckart | Dirk Goldhahn
Proceedings of the Workshop on Dataset Creation for Lower-Resourced Languages within the 13th Language Resources and Evaluation Conference

The “Web as corpus” paradigm opens opportunities for enhancing the current state of language resources for endangered and under-resourced languages. However, standard crawling strategies tend to overlook available resources of these languages in favor of already well-documented ones. Since 2016, the “Crawling Under-Resourced Languages” portal (CURL) has been contributing to bridging the gap between established crawling techniques and knowledge about relevant Web resources that is only available in the specific language communities. The aim of the CURL portal is to enlarge the amount of available text material for under-resourced languages thereby developing available datasets further and to use them as a basis for statistical evaluation and enrichment of already available resources. The application is currently provided and further developed as part of the thematic cluster “Non-Latin scripts and Under-resourced languages” in the German national research consortium Text+. In this context, its focus lies on the extraction of text material and statistical information for the data domain “Lexical resources”.


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Typical Sentences as a Resource for Valence
Uwe Quasthoff | Lars Hellan | Erik Körner | Thomas Eckart | Dirk Goldhahn | Dorothee Beermann
Proceedings of the Twelfth Language Resources and Evaluation Conference

Verb valence information can be derived from corpora by using subcorpora of typical sentences that are constructed in a language independent manner based on frequent POS structures. The inspection of typical sentences with a fixed verb in a certain position can show the valence information directly. Using verb fingerprints, consisting of the most typical sentence patterns the verb appears in, we are able to identify standard valence patterns and compare them against a language’s valence profile. With a very limited number of training data per language, valence information for other verbs can be derived as well. Based on the Norwegian valence patterns we are able to find comparative patterns in German where typical sentences are able to express the same situation in an equivalent way and can so construct verb valence pairs for a bilingual PolyVal dictionary. This contribution discusses this application with a focus on the Norwegian valence dictionary NorVal.

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Usability and Accessibility of Bantu Language Dictionaries in the Digital Age: Mobile Access in an Open Environment
Thomas Eckart | Sonja Bosch | Uwe Quasthoff | Erik Körner | Dirk Goldhahn | Simon Kaleschke
Proceedings of the first workshop on Resources for African Indigenous Languages

This contribution describes a free and open mobile dictionary app based on open dictionary data. A specific focus is on usability and user-adequate presentation of data. This includes, in addition to the alphabetical lemma ordering, other vocabulary selection, grouping, and access criteria. Beyond search functionality for stems or roots – required due to the morphological complexity of Bantu languages – grouping of lemmas by subject area of varying difficulty allows customization. A dictionary profile defines available presentation options of the dictionary data in the app and can be specified according to the needs of the respective user group. Word embeddings and similar approaches are used to link to semantically similar or related words. The underlying data structure is open for monolingual, bilingual or multilingual dictionaries and also supports the connection to complex external resources like Wordnets. The application in its current state focuses on Xhosa and Zulu dictionary data but more resources will be integrated soon.


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OSIAN: Open Source International Arabic News Corpus - Preparation and Integration into the CLARIN-infrastructure
Imad Zeroual | Dirk Goldhahn | Thomas Eckart | Abdelhak Lakhouaja
Proceedings of the Fourth Arabic Natural Language Processing Workshop

The World Wide Web has become a fundamental resource for building large text corpora. Broadcasting platforms such as news websites are rich sources of data regarding diverse topics and form a valuable foundation for research. The Arabic language is extensively utilized on the Web. Still, Arabic is relatively an under-resourced language in terms of availability of freely annotated corpora. This paper presents the first version of the Open Source International Arabic News (OSIAN) corpus. The corpus data was collected from international Arabic news websites, all being freely available on the Web. The corpus consists of about 3.5 million articles comprising more than 37 million sentences and roughly 1 billion tokens. It is encoded in XML; each article is annotated with metadata information. Moreover, each word is annotated with lemma and part-of-speech. the described corpus is processed, archived and published into the CLARIN infrastructure. This publication includes descriptive metadata via OAI-PMH, direct access to the plain text material (available under Creative Commons Attribution-Non-Commercial 4.0 International License - CC BY-NC 4.0), and integration into the WebLicht annotation platform and CLARIN’s Federated Content Search FCS.


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Preparation and Usage of Xhosa Lexicographical Data for a Multilingual, Federated Environment
Sonja Bosch | Thomas Eckart | Bettina Klimek | Dirk Goldhahn | Uwe Quasthoff
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)


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Features for Generic Corpus Querying
Thomas Eckart | Christoph Kuras | Uwe Quasthoff
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

The availability of large corpora for more and more languages enforces generic querying and standard interfaces. This development is especially relevant in the context of integrated research environments like CLARIN or DARIAH. The paper focuses on several applications and implementation details on the basis of a unified corpus format, a unique POS tag set, and prepared data for word similarities. All described data or applications are already or will be in the near future accessible via well-documented RESTful Web services. The target group are all kinds of interested persons with varying level of experience in programming or corpus query languages.


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Using Significant Word Co-occurences for the Lexical Access Problem
Rico Feist | Daniel Gerighausen | Manuel Konrad | Georg Richter | Thomas Eckart | Dirk Goldhahn | Uwe Quasthoff
Proceedings of the 4th Workshop on Cognitive Aspects of the Lexicon (CogALex)

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High Quality Word Lists as a Resource for Multiple Purposes
Uwe Quasthoff | Dirk Goldhahn | Thomas Eckart | Erla Hallsteinsdóttir | Sabine Fiedler
Proceedings of the Ninth International Conference on Language Resources and Evaluation (LREC'14)

Since 2011 the comprehensive, electronically available sources of the Leipzig Corpora Collection have been used consistently for the compilation of high quality word lists. The underlying corpora include newspaper texts, Wikipedia articles and other randomly collected Web texts. For many of the languages featured in this collection, it is the first comprehensive compilation to use a large-scale empirical base. The word lists have been used to compile dictionaries with comparable frequency data in the Frequency Dictionaries series. This includes frequency data of up to 1,000,000 word forms presented in alphabetical order. This article provides an introductory description of the data and the methodological approach used. In addition, language-specific statistical information is provided with regard to letters, word structure and structural changes. Such high quality word lists also provide the opportunity to explore comparative linguistic topics and such monolingual issues as studies of word formation and frequency-based examinations of lexical areas for use in dictionaries or language teaching. The results presented here can provide initial suggestions for subsequent work in several areas of research.

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A 500 Million Word POS-Tagged Icelandic Corpus
Thomas Eckart | Erla Hallsteinsdóttir | Sigrún Helgadóttir | Uwe Quasthoff | Dirk Goldhahn
Proceedings of the Ninth International Conference on Language Resources and Evaluation (LREC'14)

The new POS-tagged Icelandic corpus of the Leipzig Corpora Collection is an extensive resource for the analysis of the Icelandic language. As it contains a large share of all Web documents hosted under the .is top-level domain, it is especially valuable for investigations on modern Icelandic and non-standard language varieties. The corpus is accessible via a dedicated web portal and large shares are available for download. Focus of this paper will be the description of the tagging process and evaluation of statistical properties like word form frequencies and part of speech tag distributions. The latter will be in particular compared with values from the Icelandic Frequency Dictionary (IFD) Corpus.


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Building Large Monolingual Dictionaries at the Leipzig Corpora Collection: From 100 to 200 Languages
Dirk Goldhahn | Thomas Eckart | Uwe Quasthoff
Proceedings of the Eighth International Conference on Language Resources and Evaluation (LREC'12)

The Leipzig Corpora Collection offers free online access to 136 monolingual dictionaries enriched with statistical information. In this paper we describe current advances of the project in collecting and processing text data automatically for a large number of languages. Our main interest lies in languages of “low density”, where only few text data exists online. The aim of this approach is to create monolingual dictionaries and statistical information for a high number of new languages and to expand the existing dictionaries, opening up new possibilities for linguistic typology and other research. Focus of this paper will be set on the infrastructure for the automatic acquisition of large amounts of monolingual text in many languages from various sources. Preliminary results of the collection of text data will be presented. The mainly language-independent framework for preprocessing, cleaning and creating the corpora and computing the necessary statistics will also be depicted.

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The Influence of Corpus Quality on Statistical Measurements on Language Resources
Thomas Eckart | Uwe Quasthoff | Dirk Goldhahn
Proceedings of the Eighth International Conference on Language Resources and Evaluation (LREC'12)

The quality of statistical measurements on corpora is strongly related to a strict definition of the measuring process and to corpus quality. In the case of multiple result inspections, an exact measurement of previously specified parameters ensures compatibility of the different measurements performed by different researchers on possibly different objects. Hence, the comparison of different values requires an exact description of the measuring process. To illustrate this correlation the influence of different definitions for the concepts """"word"""" and """"sentence"""" is shown for several properties of large text corpora. It is also shown that corpus pre-processing strongly influences corpus size and quality as well. As an example near duplicate sentences are identified as source of many statistical irregularities. The problem of strongly varying results especially holds for Web corpora with a large set of pre-processing steps. Here, a well-defined and language independent pre-processing is indispensable for language comparison based on measured values. Conversely, irregularities found in such measurements are often a result of poor pre-processing and therefore such measurements can help to improve corpus quality.


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Íslenskur Orðasjóður – Building a Large Icelandic Corpus
Erla Hallsteinsdóttir | Thomas Eckart | Chris Biemann | Uwe Quasthoff | Matthias Richter
Proceedings of the 16th Nordic Conference of Computational Linguistics (NODALIDA 2007)