Unlike previous conll tasks, the task of coreference requires world knowledge, and most stateoftheart systems use information from resources such as wordnet, to add a layer of semantics that allows them to generalize connections between various lexicalized mentions in the data. To our knowledge, this is the rst attempt to design an mln for event coreference resolution. Despite its simplicity, our approach gives stateoftheart performance on several corpora and genres, and has also been incorporated into hybrid stateoftheart coreference systems for chinese and arabic. Training coreference resolution for world knowledge. Coreference resolution with ilpbased weighted abduction. Extracting anaphoric agreement properties from corpora. Flatworld textbooks come complete with a full range of instructor supplements, included homework system, and an easytouse customization platform, all at no extra cost. Syntactic parsing, coreference resolution, taxonomy induction, world knowledge and commonsense induction.
Lexical patterns, features and knowledge resources for. It is an important step for a lot of higher level nlp tasks that involve natural language understanding such as document summarization, question answering, and information extraction. Dataset for coreference resolution web corpus where spans are annotated with. Anaphora resolution algorithms, resources, and applications. The corefannotator finds mentions of the same entity in a text, such as when theresa may and she refer to the same person. A clusterranking approach to coreference resolution. Moreover, since there has been no attempt to apply different sources of world knowledge in combination to coreference resolution, it is not clear whether they offer complementary benefits to a resolver. In the world knowledge employed, our work is most similar to the study on twin sentences presented in rahman and ng, 2012. The coreference challenge results show that the current stateoftheart medical coreference resolution systems perform well in solving coreference across all the semantic categories, but face difficulties in solving coreference for cases that require domain knowledge. The system is developed based on knowledge poor approach in the sense that we use low levels of linguistic knowledge like morphology avoiding the need of complex knowledge like semantics, world knowledge and others. Using memetic algorithm for instance coreference resolution.
Deterministic coreference resolution based on entitycentric. Pdf dynamic knowledgebase alignment for coreference resolution. Simple coreference resolution with rich syntactic and semantic features. A smorgasbord architecture for coreference resolution in biomedical text. By reading the papers from the top nlp coreferences, i tend to think that there are two research frontiers in the field of corefernece resolution. Explicitly try to factor out world knowledge entity anonymization in daily mailcnn. Coreference resolution with world knowledge, by altaf rahman and vincent ng, acl 2011. For example, in the sentence, andrew said he would buy a car the pronoun he refers to the. As a consequence, we focus in the following on the evaluation of coreference relations only, and do not tackle the issue of evaluating noncoreferential anaphoric relations.
Currently, most of the coreference resolution systems 36 are not equipped with these knowledge resources. Question answering systems in the context of machine reading applications have also been constructed in the medical domain, for instance related to alzheimers disease. Rewarding coreference resolvers for being consistent with world knowledge. Anaphora resolution by massimo poesio overdrive rakuten. Introduction to anaphora and coreference resolution ar is an intralinguistic terminology, which means that it refers to resolving references used within the text with a same sense i. Note that several leading coreference researchers have published books e. Main proceedings of the 49th annual meeting of the association for computational linguistics. We present a neural network based coreference system that produces highdimensional vector representations for pairs of coreference clusters. This is particularly useful in other nlp tasks, including retrieving information about specific named entities, machine translation, among others. In the future additional information in the form of the output of a named entity recognizer or world knowledge could improve the models performance even more. Targeted application domain evaluation metrics for coreference resolution have three.
The coreference resolution challenge continued i2b2s efforts to release annotated clinical records to the nlp community for the advancement of the state of the art. Pdf coreference resolution with world knowledge altaf. Several other natural language processing tasks may benefit from it, such as named entities recognition, relation extraction between named entities, summarization, sentiment analysis. Home conferences conll proceedings conll shared task 11 narrative schema as world knowledge for coreference resolution. For pretraining the coreference resolution system, ontonotes 5. Instance coreference resolution is an essential problem in studying semantic web, and it is also critical for the implementation of web of data and future integration and application of semantic data. Hence, it is not clear whether these benefits can carry over. Us20090076799a1 coreference resolution in an ambiguity. We discuss the critical issues behind the practice of coreference resolution evaluation, such as the range of mentions defined. However, instead of using world knowledge for generating features in a machine learning framework, we explore inferencebased discourse processing. Narrative schema as world knowledge for coreference resolution. Coreference resolution with world knowledge acl anthology. Citeseerx coreference resolution with world knowledge.
Unsupervised learning of contextual role knowledge for coreference resolution. In this paper, we propose to use memetic algorithm ma to solve this instance coreference problem in a sequential stage, i. While world knowledge has been shown to improve learningbased coreference resolvers, the improvements were typically obtained by incorporating world knowledge into. The first one is to incorporate more features into the models, such as mentionpair model and cluste. Flatworld bringing textbook prices back down to earth. Pdf stateoftheart nlp approaches to coreference resolution. Anaphora resolution without world knowledge scielo. Oct 15, 2018 coreference resolution finds the mentions in a text that refer to the same realworld entity. Abstract while world knowledge has been shown to improve learningbased coreference resolvers, the improvements were typically obtained by incorporating world knowledge into. Secondary, most of the coreference resolution problems can only be resolved using various knowledge resources including lexical knowledge, syntactic knowledge, world knowledge, and semantic knowledge. Training coreference resolution for world knowledge i have tried with neuralcoref, end to end coresolution, allennlp, corenlp to solve for coreference resolution. This book lays out a path leading from the linguistic and cognitive basics, to classical rulebased and machine learning algorithms, to todays stateoftheart approaches, which use advanced empirically grounded techniques, automatic knowledge acquisition, and refined linguistic modeling to make a real difference in real world applications. Dynamic knowledge base alignment for coreference resolution.
The nlp domain reports great advances to the extent that a number of problems, such as partofspeech tagging, are considered to be fully solved. Successful coreference resolution often requires real world knowledge of public figures, entity relation. Our system thus offers a new paradigm for combining knowledge in rulebased systems that has implications throughout computational linguistics. Evaluating the state of the art in coreference resolution. Narrative schema as world knowledge for coreference. Amharic anaphora resolution using knowledgepoor approach. Many of the recent advances in stateoftheart coreference resolution systems have come from improvements in the underlying models, that allow to represent linguistically more robust features. Coreference chains are groups of referring expressions having the same referent. All of these do not perform well and mainly does statistical guesswork when faced with sentences containing pronouns which require world knowledge to resolve the pronoun. Coreference resolution has been an active field of research in the past several decades and plays a vital role in many areas such as information extraction, document summarization, machine translation, and question answering systems. Noun phrase np coreference resolution is the task of determining which nps in a text or dialogue refer to the same realworld entity. Nominal coreference resolution using semantic knowledge. Modelbased annotation is shown to lead to faster annotation and higher interannotator agreement, and we argue that it also opens up for an alternative approach to coreference resolution.
Though syntax does play a role in entity resolution, to some extent world knowledge or. Hence, it is not clear whether these benefits can carry over to a stronger baseline. It is an important step for a lot of higher level nlp tasks that involve natural language understanding such as document summarization, question. For example in the sentence bill said he would come, the proper noun bill and the noun he refers to the same person, namely to bill. Coreference resolution using neural mcdm and fuzzy. Rewarding coreference resolvers for being consistent with. Coreference resolution with world knowledge proceedings. The influence of consistency constraints on interpretations of coreference in spanish. We present two new coreference benchmark datasets, for english wikipedia and english teacherstudent dialogues, and evaluate stateoftheart coreference. In this study, we explored the current stateoftheart advances in the. Cntslanguage technology group, university of antwerp abstract this paper presents a machine learning approach to the resolution of coreferential relations between nominal constituents in dutch. Coreference resolution is the task of determining which mentions in a dis course refer to the same entity.
I still think about this book almost daily, years after i first. At the same time, such tasks as text summarization. This paper presents a new coreference resolution approach by incorporating. Keywords entity resolution coreference resolution anaphora.
Integer linear programming for coreference resolution 12. Coreference resolution kartik sawhney kartiks2 and rebecca wang rwang7 overview coreference resolution refers to the task of clustering different mentions referring to the same entity. Mlns are particularly wellsuited for modeling joint inference tasks in natural language processing nlp due to the. Machine translation, sometimes referred to by the abbreviation mt not to be confused with computeraided translation, machineaided human translation maht or interactive translation is a subfield of computational linguistics that investigates the use of software to translate text or speech from one language to another. This book lays out a path leading from the linguistic and cognitive basics. The systems performed better in coreference resolution when provided with ground truth mentions.
To me, expanding your mind means that a book had an impact on the way i look at the world. Coreference resolution is the task of recognizing these expressions in text and linking or chaining them. Aug 15, 2016 this book lays out a path leading from the linguistic and cognitive basics, to classical rulebased and machine learning algorithms, to todays stateoftheart approaches, which use advanced empirically grounded techniques, automatic knowledge acquisition, and refined linguistic modeling to make a real difference in real world applications. Machine learning for entity coreference resolution aaai.
Research on coreference resolution in the general english domain dates back to 1960s and 1970s. Entity coreference resolution is the task of determining. Nara institute of science and technology, nara prefecture, japan. Coreference resolution is the task of determining linguistic expressions that refer to the same real world entity in natural language. While world knowledge has been shown to improve learningbased coreference resolvers, the improvements were typically obtained by incorporating world knowledge into a fairly weak baseline resolver. International journal of computational intelligence systems.
A lightweight approach to coreference resolution for named entities in text 2 abstract. Coreference resolution with world knowledge proceedings of the. Coreference resolution is the task of finding all such expressions that refer to the same entity in a text. While world knowledge has been shown to improve learningbased coreference resolvers, the improvements were typically obtained by. In proceedings of the human language technology conference of the north american chapter of the association for computational linguistics, pages 297304. Computational analysis of referring expressions in narratives. The entire coreference graph with head words of mentions as nodes is saved as a corefchainannotation. Citeseerx document details isaac councill, lee giles, pradeep teregowda. A constraintbased hypergraph partitioning approach to. Learning dutch coreference resolution veronique hoste and walter daelemans. Coreference is defined as the relation between linguistic expressions that are referring to the same real world entity.
Utilize our full range of instructor supplements, including powerpoint slides. A lightweight approach to coreference resolution for named. However, research on coreference resolution in the clinical free text has not seen major development. This book lays out a path leading from the linguistic and cognitive basics, to classical rulebased and machine learning algorithms, to todays stateoftheart approaches, which use advanced empirically grounded techniques, automatic knowledge acquisition, and refined linguistic modeling to make a real difference in realworld applications. Despite the usefulness of world knowledge for coreference resolution, early learningbased coref. As can be seen from the above example, the referring expressions. Introduction to anaphora and coreference resolution. Improving coreference resolution by learning entitylevel. In ie tasks, this is typically restricted to finding links between previouslyextracted named entities. Opendomain question answering deals with questions about nearly anything, and can only rely on general ontologies and world knowledge. That systems struggled in solving coreference resolution for cases that required domain knowledge isnt surprising.
Also, these entities are usually present in the text and, hence, the need of world knowledge is minimal. Also, these entities are usually present in the text and, hence, the need of world knowledge is. Coreference resolution overview coreference resolution is the task of finding all expressions that refer to the same entity in a text. Coreference resolution is a challenging task, considering the required linguistic knowledge and the sophistication of language processing techniques involved. Our investigation shows that, although complex, the coreference resolution task can be targeted in a multilingual and even language independent way. Proceedings of the 49th annual meeting of the association for computational linguistics. Evaluating the state of the art in coreference resolution for. The performance of the system is evaluated using 10fold cross validation technique and experimental results are reported. I have tried with neuralcoref, end to end coresolution, allennlp, corenlp to solve for coreference resolution. The main contributions of this article are i a new approach to coreference resolution based on constraint satisfaction, using a hypergraph to represent the problem and solving it by relaxation labeling.
Advanced machine learning models for coreference resolution 11. And after serious thought, i came up with the following 22 books that caused a real shift in the way i think. As we have described in section 1, it is possible to categorize coreference. A mention, normally a noun phrase np, is a referring expression having an entity as a referent. Abstract while world knowledge has been shown to improve learningbased coreference resolvers, the improvements were typically obtained by incorporating world knowledge into a fairly weak baseline resolver. The first proposed problem is to recognize what appears in images while incorporating knowledge of spatial relationships and interactions between objects and some background knowledge knowledge of how the world works e. Applying coreference resolution for usage in dialog systems. Another paper which we want to mention here is event coreference resolution by iteratively unfolding interdependencies among events. Towards generalizable entitycentric clinical coreference resolution topic expression, information saliency and anaphora resolution testing the neogricean pragmatic theory of anaphora. Biggest open problems in natural language processing. World knowledge and expectations important in human reading barrett and nyhof, 2001. Coreference resolution with world knowledge proceedings of. However, since these heuristics are not perfect, complementing them with world knowledge would be an important step towards bringing coreference systems to the next level of performance. Understanding the values of features for coreference resolution.
Simple coreference resolution with rich syntactic and. Overall, the systems struggled in solving coreference resolution for cases that required domain knowledge. Ar is an intralinguistic terminology, which means that it refers to resolving references used within the text with a same sense i. Coreference resolution with world knowledge altaf rahman, vincent ng. A lightweight approach to coreference resolution for. For example, international business machines and ibm refer to the same real world entity. We list reference resources used for training stateoftheart systems on different languages and for introducing world knowledge at different levels of the. The task of automatic np coreference resolution is to determine which nps in a text refer to the same real world entity ng, 2010, p. Coreference resolution, conversely, concerns terms with potentially different meanings, yet referring to the same extralinguistic world entity. The annotator implements both pronominal and nominal coreference resolution. This thesis presents a lightweight approach to resolving pronominal coreference in the case when the antecedent is named entity. Coreference resolution using neural mcdm and fuzzy weighting. The task of coreference resolution has attracted considerable attention in the literature due to its importance in deep language understanding and its potential as a subtask in a variety of complex natural language processing problems. It falls under the category of the socalled knowledge poor approaches which do not rely.