Embedding Predications

Written communication is rarely a sequence of simple assertions. More often, in addition to simple assertions, authors express subjectivity, such as beliefs, speculations, opinions, intentions, and desires. Furthermore, they link statements of various kinds to form a coherent discourse that reflects their pragmatic intent. In computational semantics, extraction of simple assertions (propositional meaning) has attracted the greatest attention, while research that focuses on extra-propositional aspects of meaning has remained sparse overall and has been largely limited to narrowly defined categories, such as hedging or sentiment analysis, treated in isolation. In this thesis, we contribute to the understanding of extra-propositional meaning in natural language understanding, by providing a comprehensive account of the semantic phenomena that occur beyond simple assertions and examining how a coherent discourse is formed from lower level semantic elements. Our approach is linguistically based, and we propose a general, unified treatment of the semantic phenomena involved, within a computationally viable framework. We identify semantic embedding as the core notion involved in expressing extra-propositional meaning. The embedding framework is based on the structural distinction between embedding and atomic predications, the former corresponding to extra-propositional aspects of meaning. It incorporates the notions of predication source, modality scale, and scope. We develop an embedding categorization scheme and a dictionary based on it, which provide the necessary means to interpret extra-propositional meaning with a compositional semantic interpretation methodology. Our syntax-driven methodology exploits syntactic dependencies to construct a semantic embedding graph of a document. Traversing the graph in a bottom-up manner guided by compositional operations, we construct predications corresponding to extra-propositional semantic content, which form the basis for addressing practical tasks. We focus on text from two distinct domains: news articles from the Wall Street Journal, and scientific articles focusing on molecular biology. Adopting a task-based evaluation strategy, we consider the easy adaptability of the core framework to practical tasks that involve some extra-propositional aspect as a measure of its success. The computational tasks we consider include hedge/uncertainty detection, scope resolution, negation detection, biological event extraction, and attribution resolution. Our competitive results in these tasks demonstrate the viability of our proposal

Barry Smith an sich

Festschrift in Honor of Barry Smith on the occasion of his 65th Birthday. Published as issue 4:4 of the journal Cosmos + Taxis: Studies in Emergent Order and Organization. Includes contributions by Wolfgang Grassl, Nicola Guarino, John T. Kearns, Rudolf Lüthe, Luc Schneider, Peter Simons, Wojciech Żełaniec, and Jan Woleński

A Survey on Semantic Processing Techniques

Semantic processing is a fundamental research domain in computational linguistics. In the era of powerful pre-trained language models and large language models, the advancement of research in this domain appears to be decelerating. However, the study of semantics is multi-dimensional in linguistics. The research depth and breadth of computational semantic processing can be largely improved with new technologies. In this survey, we analyzed five semantic processing tasks, e.g., word sense disambiguation, anaphora resolution, named entity recognition, concept extraction, and subjectivity detection. We study relevant theoretical research in these fields, advanced methods, and downstream applications. We connect the surveyed tasks with downstream applications because this may inspire future scholars to fuse these low-level semantic processing tasks with high-level natural language processing tasks. The review of theoretical research may also inspire new tasks and technologies in the semantic processing domain. Finally, we compare the different semantic processing techniques and summarize their technical trends, application trends, and future directions.Comment: Published at Information Fusion, Volume 101, 2024, 101988, ISSN 1566-2535. The equal contribution mark is missed in the published version due to the publication policies. Please contact Prof. Erik Cambria for detail

Artificial Intelligence for Online Review Platforms - Data Understanding, Enhanced Approaches and Explanations in Recommender Systems and Aspect-based Sentiment Analysis

The epoch-making and ever faster technological progress provokes disruptive changes and poses pivotal challenges for individuals and organizations. In particular, artificial intelligence (AI) is a disruptive technology that offers tremendous potential for many fields such as information systems and electronic commerce. Therefore, this dissertation contributes to AI for online review platforms aiming at enabling the future for consumers, businesses and platforms by unveiling the potential of AI. To achieve this goal, the dissertation investigates six major research questions embedded in the triad of data understanding of online consumer reviews, enhanced approaches and explanations in recommender systems and aspect-based sentiment analysis

Methods for constructing an opinion network for politically controversial topics

The US presidential race, the re-election of President Hugo Chavez, and the economic crisis in Greece and other European countries are some of the controversial topics being played on the news everyday. To understand the landscape of opinions on political controversies, it would be helpful to know which politician or other stakeholder takes which position - support or opposition - on specific aspects of these topics. The work described in this thesis aims to automatically derive a map of the opinions-people network from news and other Web docu- ments. The focus is on acquiring opinions held by various stakeholders on politi- cally controversial topics. This opinions-people network serves as a knowledge- base of opinions in the form of (opinion holder) (opinion) (topic) triples. Our system to build this knowledge-base makes use of online news sources in order to extract opinions from text snippets. These sources come with a set of unique challenges. For example, processing text snippets involves not just iden- tifying the topic and the opinion, but also attributing that opinion to a specific opinion holder. This requires making use of deep parsing and analyzing the parse tree. Moreover, in order to ensure uniformity, both the topic as well the opinion holder should be mapped to canonical strings, and the topics should also be organized into a hierarchy. Our system relies on two main components: i) acquiring opinions which uses a combination of techniques to extract opinions from online news sources, and ii) organizing topics which crawls and extracts de- bates from online sources, and organizes these debates in a hierarchy of political controversial topics. We present systematic evaluations of the different compo- nents of our system, and show their high accuracies. We also present some of the different kinds of applications that require political analysis. We present some application requires political analysis such as identifying flip-floppers, political bias, and dissenters. Such applications can make use of the knowledge-base of opinions.Kontroverse Themen wie das US-Präsidentschaftsrennen, die Wiederwahl von Präsident Hugo Chavez, die Wirtschaftskrise in Griechenland sowie in anderen europäischen Ländern werden täglich in den Nachrichten diskutiert. Um die Bandbreite verschiedener Meinungen zu politischen Kontroversen zu verstehen, ist es hilfreich herauszufinden, welcher Politiker bzw. Interessenvertreter welchen Standpunkt (Pro oder Contra) bezüglich spezifischer Aspekte dieser Themen einnimmt. Diese Dissertation beschreibt ein Verfahren, welches automatisch eine Übersicht des Meinung-Mensch-Netzwerks aus aktuellen Nachrichten und anderen Web-Dokumenten ableitet. Der Fokus liegt hierbei auf dem Erfassen von Meinungen verschiedener Interessenvertreter bezüglich politisch kontroverser Themen. Dieses Meinung-Mensch-Netzwerk dient als Wissensbasis von Meinungen in Form von Tripeln: (Meinungsvertreter) (Meinung) (Thema). Um diese Wissensbasis aufzubauen, nutzt unser System Online-Nachrichten und extrahiert Meinungen aus Textausschnitten. Quellen von Online-Nachrichten stellen eine Reihe von besonderen Anforderungen an unser System. Zum Beispiel umfasst die Verarbeitung von Textausschnitten nicht nur die Identifikation des Themas und der geschilderten Meinung, sondern auch die Zuordnung der Stellungnahme zu einem spezifischen Meinungsvertreter.Dies erfordert eine tiefgründige Analyse sowie eine genaue Untersuchung des Syntaxbaumes. Um die Einheitlichkeit zu gewährleisten, müssen darüber hinaus Thema sowie Meinungsvertreter auf ein kanonisches Format abgebildet und die Themen hierarchisch angeordnet werden. Unser System beruht im Wesentlichen auf zwei Komponenten: i) Erkennen von Meinungen, welches verschiedene Techniken zur Extraktion von Meinungen aus Online-Nachrichten beinhaltet, und ii) Erkennen von Beziehungen zwischen Themen, welches das Crawling und Extrahieren von Debatten aus Online-Quellen sowie das Organisieren dieser Debatten in einer Hierarchie von politisch kontroversen Themen umfasst. Wir präsentieren eine systematische Evaluierung der verschiedenen Systemkomponenten, welche die hohe Genauigkeit der von uns entwickelten Techniken zeigt. Wir diskutieren außerdem verschiedene Arten von Anwendungen, die eine politische Analyse erfordern, wie zum Beispiel die Erkennung von Opportunisten, politische Voreingenommenheit und Dissidenten. All diese Anwendungen können durch die Wissensbasis von Meinungen umfangreich profitieren

Argumentation models and their use in corpus annotation: practice, prospects, and challenges

The study of argumentation is transversal to several research domains, from philosophy to linguistics, from the law to computer science and artificial intelligence. In discourse analysis, several distinct models have been proposed to harness argumentation, each with a different focus or aim. To analyze the use of argumentation in natural language, several corpora annotation efforts have been carried out, with a more or less explicit grounding on one of such theoretical argumentation models. In fact, given the recent growing interest in argument mining applications, argument-annotated corpora are crucial to train machine learning models in a supervised way. However, the proliferation of such corpora has led to a wide disparity in the granularity of the argument annotations employed. In this paper, we review the most relevant theoretical argumentation models, after which we survey argument annotation projects closely following those theoretical models. We also highlight the main simplifications that are often introduced in practice. Furthermore, we glimpse other annotation efforts that are not so theoretically grounded but instead follow a shallower approach. It turns out that most argument annotation projects make their own assumptions and simplifications, both in terms of the textual genre they focus on and in terms of adapting the adopted theoretical argumentation model for their own agenda. Issues of compatibility among argument-annotated corpora are discussed by looking at the problem from a syntactical, semantic, and practical perspective. Finally, we discuss current and prospective applications of models that take advantage of argument-annotated corpora

Finding Neurons in a Haystack: Case Studies with Sparse Probing

Despite rapid adoption and deployment of large language models (LLMs), the internal computations of these models remain opaque and poorly understood. In this work, we seek to understand how high-level human-interpretable features are represented within the internal neuron activations of LLMs. We train $k$-sparse linear classifiers (probes) on these internal activations to predict the presence of features in the input; by varying the value of $k$ we study the sparsity of learned representations and how this varies with model scale. With $k=1$, we localize individual neurons which are highly relevant for a particular feature, and perform a number of case studies to illustrate general properties of LLMs. In particular, we show that early layers make use of sparse combinations of neurons to represent many features in superposition, that middle layers have seemingly dedicated neurons to represent higher-level contextual features, and that increasing scale causes representational sparsity to increase on average, but there are multiple types of scaling dynamics. In all, we probe for over 100 unique features comprising 10 different categories in 7 different models spanning 70 million to 6.9 billion parameters