George Giannakopoulos


2020

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Social Web Observatory: A Platform and Method for Gathering Knowledge on Entities from Different Textual Sources
Leonidas Tsekouras | Georgios Petasis | George Giannakopoulos | Aris Kosmopoulos
Proceedings of the 12th Language Resources and Evaluation Conference

Within this work we describe a framework for the collection and summarization of information from the Web in an entity-driven manner. The framework consists of a set of appropriate workflows and the Social Web Observatory platform, which implements those workflows, supporting them through a language analysis pipeline. The pipeline includes text collection/crawling, identification of different entities, clustering of texts into events related to entities, entity-centric sentiment analysis, but also text analytics and visualization functionalities. The latter allow the user to take advantage of the gathered information as actionable knowledge: to understand the dynamics of the public opinion for a given entity over time and across real-world events. We describe the platform and the analysis functionality and evaluate the performance of the system, by allowing human users to score how the system fares in its intended purpose of summarizing entity-centered information from different sources in the Web.

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The Financial Narrative Summarisation Shared Task (FNS 2020)
Mahmoud El-Haj | Ahmed AbuRa’ed | Marina Litvak | Nikiforos Pittaras | George Giannakopoulos
Proceedings of the 1st Joint Workshop on Financial Narrative Processing and MultiLing Financial Summarisation

This paper presents the results and findings of the Financial Narrative Summarisation shared task (FNS 2020) on summarising UK annual reports. The shared task was organised as part of the 1st Financial Narrative Processing and Financial Narrative Summarisation Workshop (FNP-FNS 2020). The shared task included one main task which is the use of either abstractive or extractive summarisation methodologies and techniques to automatically summarise UK financial annual reports. FNS summarisation shared task is the first to target financial annual reports. The data for the shared task was created and collected from publicly available UK annual reports published by firms listed on the London Stock Exchange (LSE). A total number of 24 systems from 9 different teams participated in the shared task. In addition we had 2 baseline summarisers and additional 2 topline summarisers to help evaluate and compare against the results of the participants.

2019

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Proceedings of the Workshop MultiLing 2019: Summarization Across Languages, Genres and Sources
George Giannakopoulos
Proceedings of the Workshop MultiLing 2019: Summarization Across Languages, Genres and Sources

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The Summary Evaluation Task in the MultiLing - RANLP 2019 Workshop
George Giannakopoulos | Nikiforos Pittaras
Proceedings of the Workshop MultiLing 2019: Summarization Across Languages, Genres and Sources

This report covers the summarization evaluation task, proposed to the summarization community via the MultiLing 2019 Workshop of the RANLP 2019 conference. The task aims to encourage the development of automatic summarization evaluation methods closely aligned with manual, human-authored summary grades and judgements. A multilingual setting is adopted, building upon a corpus of Wikinews articles across 6 languages (English, Arabic, Romanian, Greek, Spanish and Czech). The evaluation utilizes human (golden) and machine-generated (peer) summaries, which have been assigned human evaluation scores from previous MultiLing tasks. Using these resources, the original corpus is augmented with synthetic data, combining summary texts under three different strategies (reorder, merge and replace), each engineered to introduce noise in the summary in a controlled and quantifiable way. We estimate that the utilization of such data can extract and highlight useful attributes of summary quality estimation, aiding the creation of data-driven automatic methods with an increased correlation to human summary evaluations across domains and languages. This paper provides a brief description of the summary evaluation task, the data generation protocol and the resources made available by the MultiLing community, towards improving automatic summarization evaluation.

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A Study on Game Review Summarization
George Panagiotopoulos | George Giannakopoulos | Antonios Liapis
Proceedings of the Workshop MultiLing 2019: Summarization Across Languages, Genres and Sources

Game reviews have constituted a unique means of interaction between players and companies for many years. The dynamics appearing through online publishing have significantly grown the number of comments per game, giving rise to very interesting communities. The growth has, in turn, led to a difficulty in dealing with the volume and varying quality of the comments as a source of information. This work studies whether and how game reviews can be summarized, based on the notions pre-existing in aspect-based summarization and sentiment analysis. The work provides suggested pipeline of analysis, also offering preliminary findings on whether aspects detected in a set of comments can be consistently evaluated by human users.

2017

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A Graph-based Text Similarity Measure That Employs Named Entity Information
Leonidas Tsekouras | Iraklis Varlamis | George Giannakopoulos
Proceedings of the International Conference Recent Advances in Natural Language Processing, RANLP 2017

Text comparison is an interesting though hard task, with many applications in Natural Language Processing. This work introduces a new text-similarity measure, which employs named-entities’ information extracted from the texts and the n-gram graphs’ model for representing documents. Using OpenCalais as a named-entity recognition service and the JINSECT toolkit for constructing and managing n-gram graphs, the text similarity measure is embedded in a text clustering algorithm (k-Means). The evaluation of the produced clusters with various clustering validity metrics shows that the extraction of named entities at a first step can be profitable for the time-performance of similarity measures that are based on the n-gram graph representation without affecting the overall performance of the NLP task.

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Proceedings of the MultiLing 2017 Workshop on Summarization and Summary Evaluation Across Source Types and Genres
George Giannakopoulos | Elena Lloret | John M. Conroy | Josef Steinberger | Marina Litvak | Peter Rankel | Benoit Favre
Proceedings of the MultiLing 2017 Workshop on Summarization and Summary Evaluation Across Source Types and Genres

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MultiLing 2017 Overview
George Giannakopoulos | John Conroy | Jeff Kubina | Peter A. Rankel | Elena Lloret | Josef Steinberger | Marina Litvak | Benoit Favre
Proceedings of the MultiLing 2017 Workshop on Summarization and Summary Evaluation Across Source Types and Genres

In this brief report we present an overview of the MultiLing 2017 effort and workshop, as implemented within EACL 2017. MultiLing is a community-driven initiative that pushes the state-of-the-art in Automatic Summarization by providing data sets and fostering further research and development of summarization systems. This year the scope of the workshop was widened, bringing together researchers that work on summarization across sources, languages and genres. We summarize the main tasks planned and implemented this year, the contributions received, and we also provide insights on next steps.

2015

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MultiLing 2015: Multilingual Summarization of Single and Multi-Documents, On-line Fora, and Call-center Conversations
George Giannakopoulos | Jeff Kubina | John Conroy | Josef Steinberger | Benoit Favre | Mijail Kabadjov | Udo Kruschwitz | Massimo Poesio
Proceedings of the 16th Annual Meeting of the Special Interest Group on Discourse and Dialogue

2014

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NOMAD: Linguistic Resources and Tools Aimed at Policy Formulation and Validation
George Kiomourtzis | George Giannakopoulos | Georgios Petasis | Pythagoras Karampiperis | Vangelis Karkaletsis
Proceedings of the Ninth International Conference on Language Resources and Evaluation (LREC'14)

The NOMAD project (Policy Formulation and Validation through non Moderated Crowd-sourcing) is a project that supports policy making, by providing rich, actionable information related to how citizens perceive different policies. NOMAD automatically analyzes citizen contributions to the informal web (e.g. forums, social networks, blogs, newsgroups and wikis) using a variety of tools. These tools comprise text retrieval, topic classification, argument detection and sentiment analysis, as well as argument summarization. NOMAD provides decision-makers with a full arsenal of solutions starting from describing a domain and a policy to applying content search and acquisition, categorization and visualization. These solutions work in a collaborative manner in the policy-making arena. NOMAD, thus, embeds editing, analysis and visualization technologies into a concrete framework, applicable in a variety of policy-making and decision support settings In this paper we provide an overview of the linguistic tools and resources of NOMAD.

2013

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Multi-document multilingual summarization corpus preparation, Part 1: Arabic, English, Greek, Chinese, Romanian
Lei Li | Corina Forascu | Mahmoud El-Haj | George Giannakopoulos
Proceedings of the MultiLing 2013 Workshop on Multilingual Multi-document Summarization

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Multi-document multilingual summarization corpus preparation, Part 2: Czech, Hebrew and Spanish
Michael Elhadad | Sabino Miranda-Jiménez | Josef Steinberger | George Giannakopoulos
Proceedings of the MultiLing 2013 Workshop on Multilingual Multi-document Summarization

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Multi-document multilingual summarization and evaluation tracks in ACL 2013 MultiLing Workshop
George Giannakopoulos
Proceedings of the MultiLing 2013 Workshop on Multilingual Multi-document Summarization

2009

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Sentiment Analysis of Figurative Language using a Word Sense Disambiguation Approach
Vassiliki Rentoumi | George Giannakopoulos | Vangelis Karkaletsis | George A. Vouros
Proceedings of the International Conference RANLP-2009