Hybrid discourse modeling and summarization for a speech-to-speech translation system

The thesis discusses two parts of the speech-to-speech translation system VerbMobil: the dialogue model and one of its applications, multilingual summary generation. In connection with the dialogue model, two topics are of special interest: (a) the use of a default unification operation called overlay as the fundamental operation for dialogue management; and (b) an intentional model that is able to describe intentions in dialogue on five levels in a language-independent way. Besides the actual generation algorithm developed, we present a comprehensive evaluation of the summarization functionality. In addition to precision and recall, a new characterization - confabulation - is defined that provides a more precise understanding of the performance of complex natural language processing systems.Die vorliegende Arbeit behandelt hauptsächlich zwei Themen, die für das VerbMobil-System, ein Übersetzungssystem gesprochener Spontansprache, entwickelt wurden: das Dialogmodell und als Applikation die multilinguale Generierung von Ergebnissprotokollen. Für die Dialogmodellierung sind zwei Themen von besonderem Interesse. Das erste behandelt eine in der vorliegenden Arbeit formalisierte Default-Unifikations-Operation namens Overlay, die als fundamentale Operation für Diskursverarbeitung dient. Das zweite besteht aus einem intentionalen Modell, das Intentionen eines Dialogs auf fünf Ebenen in einer sprachunabhängigen Repräsentation darstellt. Neben dem für die Protokollgenerierung entwickelten Generierungsalgorithmus wird eine umfassende Evaluation zur Protokollgenerierungsfunktionalität vorgestellt. Zusätzlich zu "precision" und "recall" wird ein neues Maß - Konfabulation (Engl.: "confabulation") - vorgestellt, das eine präzisere Charakterisierung der Qualität eines komplexen Sprachverarbeitungssystems ermöglicht

Hybrid discourse modeling and summarization for a speech-to-speech translation system

The thesis discusses two parts of the speech-to-speech translation system VerbMobil: the dialogue model and one of its applications, multilingual summary generation. In connection with the dialogue model, two topics are of special interest: (a) the use of a default unification operation called overlay as the fundamental operation for dialogue management; and (b) an intentional model that is able to describe intentions in dialogue on five levels in a language-independent way. Besides the actual generation algorithm developed, we present a comprehensive evaluation of the summarization functionality. In addition to precision and recall, a new characterization - confabulation - is defined that provides a more precise understanding of the performance of complex natural language processing systems.Die vorliegende Arbeit behandelt hauptsächlich zwei Themen, die für das VerbMobil-System, ein Übersetzungssystem gesprochener Spontansprache, entwickelt wurden: das Dialogmodell und als Applikation die multilinguale Generierung von Ergebnissprotokollen. Für die Dialogmodellierung sind zwei Themen von besonderem Interesse. Das erste behandelt eine in der vorliegenden Arbeit formalisierte Default-Unifikations-Operation namens Overlay, die als fundamentale Operation für Diskursverarbeitung dient. Das zweite besteht aus einem intentionalen Modell, das Intentionen eines Dialogs auf fünf Ebenen in einer sprachunabhängigen Repräsentation darstellt. Neben dem für die Protokollgenerierung entwickelten Generierungsalgorithmus wird eine umfassende Evaluation zur Protokollgenerierungsfunktionalität vorgestellt. Zusätzlich zu "precision" und "recall" wird ein neues Maß - Konfabulation (Engl.: "confabulation") - vorgestellt, das eine präzisere Charakterisierung der Qualität eines komplexen Sprachverarbeitungssystems ermöglicht

Language strategies for the domain of colour

This book presents a major leap forward in the understanding of colour by showing how richer descriptions of colour samples can be operationalized in agent-based models. Four different language strategies are explored: the basic colour strategy, the graded membership strategy, the category combination strategy and the basic modification strategy. These strategies are firmly rooted in empirical observations in natural languages, with a focus on compositionality at both the syntactic and semantic level. Through a series of in-depth experiments, this book discerns the impact of the environment, language and embodiment on the formation of basic colour systems. Finally, the experiments demonstrate how language users can invent their own language strategies of increasing complexity by combining primitive cognitive operators, and how these strategies can be aligned between language users through linguistic interactions

Language strategies for the domain of colour

This book presents a major leap forward in the understanding of colour by showing how richer descriptions of colour samples can be operationalized in agent-based models. Four different language strategies are explored: the basic colour strategy, the graded membership strategy, the category combination strategy and the basic modification strategy. These strategies are firmly rooted in empirical observations in natural languages, with a focus on compositionality at both the syntactic and semantic level. Through a series of in-depth experiments, this book discerns the impact of the environment, language and embodiment on the formation of basic colour systems. Finally, the experiments demonstrate how language users can invent their own language strategies of increasing complexity by combining primitive cognitive operators, and how these strategies can be aligned between language users through linguistic interactions

Language strategies for the domain of colour

This book presents a major leap forward in the understanding of colour by showing how richer descriptions of colour samples can be operationalized in agent-based models. Four different language strategies are explored: the basic colour strategy, the graded membership strategy, the category combination strategy and the basic modification strategy. These strategies are firmly rooted in empirical observations in natural languages, with a focus on compositionality at both the syntactic and semantic level. Through a series of in-depth experiments, this book discerns the impact of the environment, language and embodiment on the formation of basic colour systems. Finally, the experiments demonstrate how language users can invent their own language strategies of increasing complexity by combining primitive cognitive operators, and how these strategies can be aligned between language users through linguistic interactions

Evaluating Parsers with Dependency Constraints

Many syntactic parsers now score over 90% on English in-domain evaluation, but the remaining errors have been challenging to address and difficult to quantify. Standard parsing metrics provide a consistent basis for comparison between parsers, but do not illuminate what errors remain to be addressed. This thesis develops a constraint-based evaluation for dependency and Combinatory Categorial Grammar (CCG) parsers to address this deficiency. We examine the constrained and cascading impact, representing the direct and indirect effects of errors on parsing accuracy. This identifies errors that are the underlying source of problems in parses, compared to those which are a consequence of those problems. Kummerfeld et al. (2012) propose a static post-parsing analysis to categorise groups of errors into abstract classes, but this cannot account for cascading changes resulting from repairing errors, or limitations which may prevent the parser from applying a repair. In contrast, our technique is based on enforcing the presence of certain dependencies during parsing, whilst allowing the parser to choose the remainder of the analysis according to its grammar and model. We draw constraints for this process from gold-standard annotated corpora, grouping them into abstract error classes such as NP attachment, PP attachment, and clause attachment. By applying constraints from each error class in turn, we can examine how parsers respond when forced to correctly analyse each class. We show how to apply dependency constraints in three parsers: the graph-based MSTParser (McDonald and Pereira, 2006) and the transition-based ZPar (Zhang and Clark, 2011b) dependency parsers, and the C&C CCG parser (Clark and Curran, 2007b). Each is widely-used and influential in the field, and each generates some form of predicate-argument dependencies. We compare the parsers, identifying common sources of error, and differences in the distribution of errors between constrained and cascaded impact. Our work allows us to contrast the implementations of each parser, and how they respond to constraint application. Using our analysis, we experiment with new features for dependency parsing, which encode the frequency of proposed arcs in large-scale corpora derived from scanned books. These features are inspired by and extend on the work of Bansal and Klein (2011). We target these features at the most notable errors, and show how they address some, but not all of the difficult attachments across newswire and web text. CCG parsing is particularly challenging, as different derivations do not always generate different dependencies. We develop dependency hashing to address semantically redundant parses in n-best CCG parsing, and demonstrate its necessity and effectiveness. Dependency hashing substantially improves the diversity of n-best CCG parses, and improves a CCG reranker when used for creating training and test data. We show the intricacies of applying constraints to C&C, and describe instances where applying constraints causes the parser to produce a worse analysis. These results illustrate how algorithms which are relatively straightforward for constituency and dependency parsers are non-trivial to implement in CCG. This work has explored dependencies as constraints in dependency and CCG parsing. We have shown how dependency hashing can efficiently eliminate semantically redundant CCG n-best parses, and presented a new evaluation framework based on enforcing the presence of dependencies in the output of the parser. By otherwise allowing the parser to proceed as it would have, we avoid the assumptions inherent in other work. We hope this work will provide insights into the remaining errors in parsing, and target efforts to address those errors, creating better syntactic analysis for downstream applications

The evolution of grounded spatial language

This book presents groundbreaking robotic experiments on how and why spatial language evolves. It provides detailed explanations of the origins of spatial conceptualization strategies, spatial categories, landmark systems and spatial grammar by tracing the interplay of environmental conditions, communicative and cognitive pressures. The experiments discussed in this book go far beyond previous approaches in grounded language evolution. For the first time, agents can evolve not only particular lexical systems but also evolve complex conceptualization strategies underlying the emergence of category systems and compositional semantics. Moreover, many issues in cognitive science, ranging from perception and conceptualization to language processing, had to be dealt with to instantiate these experiments, so that this book contributes not only to the study of language evolution but to the investigation of the cognitive bases of spatial language as well

The evolution of grounded spatial language

This book presents groundbreaking robotic experiments on how and why spatial language evolves. It provides detailed explanations of the origins of spatial conceptualization strategies, spatial categories, landmark systems and spatial grammar by tracing the interplay of environmental conditions, communicative and cognitive pressures. The experiments discussed in this book go far beyond previous approaches in grounded language evolution. For the first time, agents can evolve not only particular lexical systems but also evolve complex conceptualization strategies underlying the emergence of category systems and compositional semantics. Moreover, many issues in cognitive science, ranging from perception and conceptualization to language processing, had to be dealt with to instantiate these experiments, so that this book contributes not only to the study of language evolution but to the investigation of the cognitive bases of spatial language as well

Lenient Default Unification for Robust Processing within Unification Based Grammar Formalisms

This paper describes new default unification, lenient default unification. It works efficiently, and gives more informative results because it maximizes the amount of information in the result, while other default unification maximizes it in the default. We also describe robust processing within the framework of HPSG. We extract grammar rules from the results of robust parsing using lenient default unification. The results of a series of experiments show that parsing with the extracted rules works robustly, and the coverage of a manually-developed HPSG grammar for Penn Treebank was greatly increased with a little overgeneration