Commonsense Properties from Query Logs and Question Answering Forums

Commonsense knowledge about object properties, human behavior and general concepts is crucial for robust AI applications. However, automatic acquisition of this knowledge is challenging because of sparseness and bias in online sources. This paper presents Quasimodo, a methodology and tool suite for distilling commonsense properties from non-standard web sources. We devise novel ways of tapping into search-engine query logs and QA forums, and combining the resulting candidate assertions with statistical cues from encyclopedias, books and image tags in a corroboration step. Unlike prior work on commonsense knowledge bases, Quasimodo focuses on salient properties that are typically associated with certain objects or concepts. Extensive evaluations, including extrinsic use-case studies, show that Quasimodo provides better coverage than state-of-the-art baselines with comparable quality

Advanced Semantics for Commonsense Knowledge Extraction

Commonsense knowledge (CSK) about concepts and their properties is useful for AI applications such as robust chatbots. Prior works like ConceptNet, TupleKB and others compiled large CSK collections, but are restricted in their expressiveness to subject-predicate-object (SPO) triples with simple concepts for S and monolithic strings for P and O. Also, these projects have either prioritized precision or recall, but hardly reconcile these complementary goals. This paper presents a methodology, called Ascent, to automatically build a large-scale knowledge base (KB) of CSK assertions, with advanced expressiveness and both better precision and recall than prior works. Ascent goes beyond triples by capturing composite concepts with subgroups and aspects, and by refining assertions with semantic facets. The latter are important to express temporal and spatial validity of assertions and further qualifiers. Ascent combines open information extraction with judicious cleaning using language models. Intrinsic evaluation shows the superior size and quality of the Ascent KB, and an extrinsic evaluation for QA-support tasks underlines the benefits of Ascent.Comment: Web interface available at https://ascent.mpi-inf.mpg.d

Advanced Semantics for Commonsense Knowledge Extraction

Commonsense knowledge (CSK) about concepts and their properties is useful for AI applications such as robust chatbots. Prior works like ConceptNet, TupleKB and others compiled large CSK collections, but are restricted in their expressiveness to subject-predicate-object (SPO) triples with simple concepts for S and monolithic strings for P and O. Also, these projects have either prioritized precision or recall, but hardly reconcile these complementary goals. This paper presents a methodology, called Ascent, to automatically build a large-scale knowledge base (KB) of CSK assertions, with advanced expressiveness and both better precision and recall than prior works. Ascent goes beyond triples by capturing composite concepts with subgroups and aspects, and by refining assertions with semantic facets. The latter are important to express temporal and spatial validity of assertions and further qualifiers. Ascent combines open information extraction with judicious cleaning using language models. Intrinsic evaluation shows the superior size and quality of the Ascent KB, and an extrinsic evaluation for QA-support tasks underlines the benefits of Ascent

Negative Statements Considered Useful

Knowledge bases (KBs), pragmatic collections of knowledge about notable entities, are an important asset in applications such as search, question answering and dialogue. Rooted in a long tradition in knowledge representation, all popular KBs only store positive information, while they abstain from taking any stance towards statements not contained in them. In this paper, we make the case for explicitly stating interesting statements which are not true. Negative statements would be important to overcome current limitations of question answering, yet due to their potential abundance, any effort towards compiling them needs a tight coupling with ranking. We introduce two approaches towards compiling negative statements. (i) In peer-based statistical inferences, we compare entities with highly related entities in order to derive potential negative statements, which we then rank using supervised and unsupervised features. (ii) In query-log-based text extraction, we use a pattern-based approach for harvesting search engine query logs. Experimental results show that both approaches hold promising and complementary potential. Along with this paper, we publish the first datasets on interesting negative information, containing over 1.1M statements for 100K popular Wikidata entities

Inside {ASCENT}: {E}xploring a Deep Commonsense Knowledge Base and its Usage in Question Answering

ASCENT is a fully automated methodology for extracting and consolidating commonsense assertions from web contents (Nguyen et al., WWW 2021). It advances traditional triple-based commonsense knowledge representation by capturing semantic facets like locations and purposes, and composite concepts, i.e., subgroups and related aspects of subjects. In this demo, we present a web portal that allows users to understand its construction process, explore its content, and observe its impact in the use case of question answering. The demo website and an introductory video are both available online

Do Children Texts Hold The Key To Commonsense Knowledge?

Compiling comprehensive repositories of commonsense knowledge is along-standing problem in AI. Many concerns revolve around the issue ofreporting bias, i.e., that frequency in text sources is not a good proxy forrelevance or truth. This paper explores whether children's texts hold the keyto commonsense knowledge compilation, based on the hypothesis that such contentmakes fewer assumptions on the reader's knowledge, and therefore spells outcommonsense more explicitly. An analysis with several corpora shows thatchildren's texts indeed contain much more, and more typical commonsenseassertions. Moreover, experiments show that this advantage can be leveraged inpopular language-model-based commonsense knowledge extraction settings, wheretask-unspecific fine-tuning on small amounts of children texts (childBERT)already yields significant improvements. This provides a refreshing perspectivedifferent from the common trend of deriving progress from ever larger modelsand corpora.<br

Enriching open-world knowledge graphs with expressive negative statements

Machine knowledge about entities and their relationships has been a long-standing goal for AI researchers. Over the last 15 years, thousands of public knowledge graphs have been automatically constructed from various web sources. They are crucial for use cases such as search engines. Yet, existing web-scale knowledge graphs focus on collecting positive statements, and store very little to no negatives. Due to their incompleteness, the truth of absent information remains unknown, which compromises the usability of the knowledge graph. In this dissertation: First, I make the case for selective materialization of salient negative statements in open-world knowledge graphs. Second, I present our methods to automatically infer them from encyclopedic and commonsense knowledge graphs, by locally inferring closed-world topics from reference comparable entities. I then discuss our evaluation fin-dings on metrics such as correctness and salience. Finally, I conclude with open challenges and future opportunities.Machine knowledge about entities and their relationships has been a long-standing goal for AI researchers. Over the last 15 years, thousands of public knowledge graphs have been automatically constructed from various web sources. They are crucial for use cases such as search engines. Yet, existing web-scale knowledge graphs focus on collecting positive statements, and store very little to no negatives. Due to their incompleteness, the truth of absent information remains unknown, which compromises the usability of the knowledge graph. In this dissertation: First, I make the case for selective materialization of salient negative statements in open-world knowledge graphs. Second, I present our methods to automatically infer them from encyclopedic and commonsense knowledge graphs, by locally inferring closed-world topics from reference comparable entities. I then discuss our evaluation fin-dings on metrics such as correctness and salience. Finally, I conclude with open challenges and future opportunities.Wissensgraphen über Entitäten und ihre Attribute sind eine wichtige Komponente vieler KI-Anwendungen. Wissensgraphen im Webmaßstab speichern fast nur positive Aussagen und übersehen negative Aussagen. Aufgrund der Unvollständigkeit von Open-World-Wissensgraphen werden fehlende Aussagen als unbekannt und nicht als falsch betrachtet. Diese Dissertation plädiert dafür, Wissensgraphen mit informativen Aussagen anzureichern, die nicht gelten, und so ihren Mehrwert für Anwendungen wie die Beantwortung von Fragen und die Zusammenfassung von Entitäten zu verbessern. Mit potenziell Milliarden negativer Aussagen von Kandidaten bewältigen wir vier Hauptherausforderungen. 1. Korrektheit (oder Plausibilität) negativer Aussagen: Unter der Open-World-Annahme (OWA) reicht es nicht aus, zu prüfen, ob ein negativer Kandidat im Wissensgraphen nicht explizit als positiv angegeben ist, da es sich möglicherweise um eine fehlende Aussage handeln kann. Von entscheidender Bedeutung sind Methoden zur Prüfung großer Kandidatengruppen, und zur Beseitigung falsch positiver Ergebnisse. 2. Bedeutung negativer Aussagen: Die Menge korrekter negativer Aussagen ist sehr groß, aber voller trivialer oder unsinniger Aussagen, z. B. “Eine Katze kann keine Daten speichern.”. Es sind Methoden zur Quantifizierung der Aussagekraft von Negativen erforderlich. 3. Abdeckung der Themen: Abhängig von der Datenquelle und den Methoden zum Abrufen von Kandidaten erhalten einige Themen oder Entitäten in demWissensgraphen möglicherweise keine negativen Kandidaten. Methoden müssen die Fähigkeit gewährleisten, Negative über fast jede bestehende Entität zu entdecken. 4. Komplexe negative Aussagen: In manchen Fällen erfordert das Ausdrücken einer Negation mehr als ein Wissensgraphen-Tripel. Beispielsweise ist “Einstein hat keine Ausbildung erhalten” eine inkorrekte Negation, aber “Einstein hat keine Ausbildung an einer US-amerikanischen Universität erhalten” ist korrekt. Es werden Methoden zur Erzeugung komplexer Negationen benötigt. Diese Dissertation geht diese Herausforderungen wie folgt an. 1. Wir plädieren zunächst für die selektive Materialisierung negativer Aussagen über Entitäten in enzyklopädischen (gut kanonisierten) Open-World-Wissensgraphen, und definieren formal drei Arten negativer Aussagen: fundiert, universell abwesend und konditionierte negative Aussagen. Wir stellen die Peer-basierte Negationsinferenz-Methode vor, um Listen hervorstechender Negationen über Entitäten zu erstellen. Die Methode berechnet relevante Peers für eine bestimmte Eingabeentität und verwendet ihre positiven Eigenschaften, um Erwartungen für die Eingabeentität festzulegen. Eine Erwartung, die nicht erfüllt ist, ist ein unmittelbar negativer Kandidat und wird dann anhand von Häufigkeits-, Wichtigkeits- und Unerwartetheitsmetriken bewertet. 2. Wir schlagen die Methode musterbasierte Abfrageprotokollextraktion vor, um hervorstechende Negationen aus umfangreichen Textquellen zu extrahieren. Diese Methode extrahiert hervorstechende Negationen über eine Entität, indem sie große Korpora, z.B., die Anfrageprotokolle von Suchmaschinen, unter Verwendung einiger handgefertigter Muster mit negativen Schlüsselwörtern sammelt. 3. Wir führen die UnCommonsense-Methode ein, um hervorstechende negative Phrasen über alltägliche Konzepte in weniger kanonisierten commonsense-KGs zu generieren. Diese Methode ist für die Negationsinferenz, Prüfung und Einstufung kurzer Phrasen in natürlicher Sprache konzipiert. Sie berechnet vergleichbare Konzepte für ein bestimmtes Zielkonzept, leitet aus dem Vergleich ihrer positiven Kandidaten Negationen ab, und prüft diese Kandidaten im Vergleich zum Wissensgraphen selbst, sowie mit Sprachmodellen (LMs) als externer Wissensquelle. Schließlich werden die Kandidaten mithilfe semantischer Ähnlichkeitserkennungshäufigkeitsmaßen eingestuft. 4. Um die Exploration unserer Methoden und ihrer Ergebnisse zu erleichtern, implementieren wir zwei Prototypensysteme. In Wikinegata wird ein System zur Präsentation der Peer-basierten Methode entwickelt, mit dem Benutzer negative Aussagen über 500K Entitäten aus 11 Klassen untersuchen und verschiedene Parameter der Peer-basierten Inferenzmethode anpassen können. Sie können den Wissensgraphen auch mithilfe einer Suchmaske mit negierten Prädikaten befragen. Im UnCommonsense-System können Benutzer genau prüfen, was die Methode bei jedem Schritt hervorbringt, sowie Negationen zu 8K alltäglichen Konzepten durchsuchen. Darüber hinaus erstellen wir mithilfe der Peer-basierten Negationsinferenzmethode den ersten groß angelegten Datensatz zu Demografie und Ausreißern in Interessengemeinschaften und zeigen dessen Nützlichkeit in Anwendungsfällen wie der Identifizierung unterrepräsentierter Gruppen. 5. Wir veröffentlichen alle in diesen Projekten erstellten Datensätze und Quellcodes unter https://www.mpi-inf.mpg.de/negation-in-kbs und https://www.mpi-inf.mpg.de/Uncommonsense

Joint Reasoning for Multi-Faceted Commonsense Knowledge

Commonsense knowledge (CSK) supports a variety of AI applications, from visual understanding to chatbots. Prior works on acquiring CSK, such as ConceptNet, have compiled statements that associate concepts, like everyday objects or activities, with properties that hold for most or some instances of the concept. Each concept is treated in isolation from other concepts, and the only quantitative measure (or ranking) of properties is a confidence score that the statement is valid. This paper aims to overcome these limitations by introducing a multi-faceted model of CSK statements and methods for joint reasoning over sets of inter-related statements. Our model captures four different dimensions of CSK statements: plausibility, typicality, remarkability and salience, with scoring and ranking along each dimension. For example, hyenas drinking water is typical but not salient, whereas hyenas eating carcasses is salient. For reasoning and ranking, we develop a method with soft constraints, to couple the inference over concepts that are related in in a taxonomic hierarchy. The reasoning is cast into an integer linear programming (ILP), and we leverage the theory of reduction costs of a relaxed LP to compute informative rankings. This methodology is applied to several large CSK collections. Our evaluation shows that we can consolidate these inputs into much cleaner and more expressive knowledge. Results are available at https://dice.mpi-inf.mpg.de