Archive for the ‘Named Entity Mining’ Category

Analysis of Named Entity Recognition and Linking for Tweets

Friday, October 24th, 2014

Analysis of Named Entity Recognition and Linking for Tweets by Leon Derczynski, et al.

Abstract:

Applying natural language processing for mining and intelligent information access to tweets (a form of microblog) is a challenging, emerging research area. Unlike carefully authored news text and other longer content, tweets pose a number of new challenges, due to their short, noisy, context-dependent, and dynamic nature. Information extraction from tweets is typically performed in a pipeline, comprising consecutive stages of language identi cation, tokenisation, part-of-speech tagging, named entity recognition and entity disambiguation (e.g. with respect to DBpedia). In this work, we describe a new Twitter entity disambiguation dataset, and conduct an empirical analysis of named entity recognition and disambiguation, investigating how robust a number of state-of-the-art systems are on such noisy texts, what the main sources of error are, and which problems should be further investigated to improve the state of the art.

A detailed review of existing solutions for mining tweets, where they fail along and why.

A comparison to spur tweet research:

Tweets Per Day > 500,000,000 Derczynski, p. 2
Annotated Tweets < 10,000 Derczynski, p. 27

Let’s see: 500,000,000 / 10,000 = 50,000.

The number of tweet per day is more than 50,000 times the number of tweets annotated with named entity types.

It may just be me but that sounds like the sort of statement you would see in a grant proposal to increase the number of annotated tweets.

Yes?

I first saw this in a tweet by Diana Maynard.

Named Entity Recognition: A Literature Survey

Friday, September 19th, 2014

Named Entity Recognition: A Literature Survey by Rahul Sharnagat.

Abstract:

In this report, we explore various methods that are applied to solve NER. In section 1, we introduce the named entity problem. In section 2, various named entity recognition methods are discussed in three three broad categories of machine learning paradigm and explore few learning techniques in them. In the first part, we discuss various supervised techniques. Subsequently we move to semi-supervised and unsupervised techniques. In the end we discuss about the method from deep learning to solve NER.

If you are new to the named entity recognition issue or want to pass on an introduction, this may be the paper for you. It covers all the high points with a three page bibliography to get your started in the literature.

I first saw this in a tweet by Christopher.

Tokenizing and Named Entity Recognition with Stanford CoreNLP

Friday, September 19th, 2014

Tokenizing and Named Entity Recognition with Stanford CoreNLP by Sujit Pal.

From the post:

I got into NLP using Java, but I was already using Python at the time, and soon came across the Natural Language Tool Kit (NLTK), and just fell in love with the elegance of its API. So much so that when I started working with Scala, I figured it would be a good idea to build a NLP toolkit with an API similar to NLTKs, primarily as a way to learn NLP and Scala but also to build something that would be as enjoyable to work with as NLTK and have the benefit of Java’s rich ecosystem.

The project is perenially under construction, and serves as a test bed for my NLP experiments. In the past, I have used OpenNLP and LingPipe to build Tokenizer implementations that expose an API similar to NLTK’s. More recently, I have built an Named Entity Recognizer (NER) with OpenNLP’s NameFinder. At the recommendation of one of my readers, I decided to take a look at Stanford CoreNLP, with which I ended up building a Tokenizer and a NER implementation. This post describes that work.

Truly a hard core way to learn NLP and Scala!

Excellent!

Looking forward to hearing more about this project.

Book-NLP

Friday, June 20th, 2014

Book-NLP: Natural language processing pipeline for book-length documents.

From the webpage:

BookNLP is a natural language processing pipeline that scales to books and other long documents (in English), including:

  • Part-of-speech tagging (Stanford)
  • Dependency parsing (MaltParser)
  • Named entity recognition (Stanford)
  • Character name clustering (e.g., “Tom”, “Tom Sawyer”, “Mr. Sawyer”, “Thomas Sawyer” -> TOM_SAWYER)
  • Quotation speaker identification
  • Pronominal coreference resolution

I can think of several classes of documents where this would be useful. Congressional hearing documents for example. Agency reports would be another.

Not the final word for mapping but certainly an assist to an author.

Evaluating Entity Linking with Wikipedia

Monday, April 28th, 2014

Evaluating Entity Linking with Wikipedia by Ben Hachey, et al.

Abstract:

Named Entity Linking (NEL) grounds entity mentions to their corresponding node in a Knowledge Base (KB). Recently, a number of systems have been proposed for linking entity mentions in text to Wikipedia pages. Such systems typically search for candidate entities and then disambiguate them, returning either the best candidate or NIL. However, comparison has focused on disambiguation accuracy, making it difficult to determine how search impacts performance. Furthermore, important approaches from the literature have not been systematically compared on standard data sets.

We reimplement three seminal NEL systems and present a detailed evaluation of search strategies. Our experiments find that coreference and acronym handling lead to substantial improvement, and search strategies account for much of the variation between systems. This is an interesting finding, because these aspects of the problem have often been neglected in the literature, which has focused largely on complex candidate ranking algorithms.

A very deep survey of entity linking literature (including record linkage) and implementation of three complete entity linking systems for comparison.

At forty-eight (48) pages it isn’t a quick read but should be your starting point for pushing the boundaries on entity linking research.

I first saw this in a tweet by Alyona Medelyan.

Using NLTK for Named Entity Extraction

Sunday, April 27th, 2014

Using NLTK for Named Entity Extraction by Emily Daniels.

From the post:

Continuing on from the previous project, I was able to augment the functions that extract character names using NLTK’s named entity module and an example I found online, building my own custom stopwords list to run against the returned names to filter out frequently used words like “Come”, “Chapter”, and “Tell” which were caught by the named entity functions as potential characters but are in fact just terms in the story.

Whether you are trusting your software or using human proofing, named entity extraction is a key task in mining data.

Having extracted named entities, the harder task is uncovering relationships between them that may not be otherwise identified.

Challenging with the text of Oliver Twist but even more difficult when mining donation records and the Congressional record.

Day 14: Stanford NER…

Monday, November 11th, 2013

Day 14: Stanford NER–How To Setup Your Own Name, Entity, and Recognition Server in the Cloud by Shekhar Gulati.

From the post:

I am not a huge fan of machine learning or natural text processing (NLP) but I always have ideas in mind which require them. The idea that I will explore during this post is the ability to build a real time job search engine using twitter data. Tweets will contain the name of the company which if offering a job, the location of the job, and name of the contact person at the company. This requires us to parse the tweet for Person, Location, and Organisation. This type of problem falls under Named Entity Recognition.

A continuation of Shekhar’s Learning 30 Technologies in 30 Days… but one that merits a special shout out.

In part because you can consume the entities that other “recognize” or you can be in control of the recognition process.

It isn’t easy but on the other hand, it isn’t free from hidden choices and selection biases.

I would prefer those were my hidden choices and selection biases, if you don’t mind. 😉

Named Entity Recognition (NER) in Solr

Friday, August 2nd, 2013

Named Entity Recognition (NER) in Solr

From the post:

Named Entity Recognition, or NER for short, is a powerful paradigm which causes entities to be recognized within text. Typically these objects can be places, organizations or people. For example, given the phrase “Jon works at Searchbox”, a good NER would return that Jon is a person and Searchbox is an organization. Why is this powerful, especially in Solr? Using this information we can not only propose better suggestions for users searching for things, but using Solr faceting capability we’ll have the ability to facet directly on organizations (or people) without having to manually identify them in all of the documents.

In this blog post, extending from our two previous slideshares on how to develop search components and request handlers, we’ll teach you how to directly embed Stanford’s NER library into a production ready plugin which provides all of the mentioned benefits. We of course provide the full source code packaging here.

Very nice walk through on entity recognition with Solr.

Thought occurs to me that every instance of an entity that is recognized, could be presented to a user as occurrences of that entity. Plugging that search result into a topic that represents the subject.

So there is some static aspect to the topic map, the topic for that subject and a dynamic aspect, being the search results presented as occurrences.

You could enter information or relationships you discover in the occurrences on the static side of the map. Let software manage metadata from the document containing the occurrence.

Named Entities in Law & Order Episodes

Monday, July 22nd, 2013

Named Entities in Law & Order Episodes by Yhat.

A worked example of using natural language processing on a corpus of viewer summaries of episodes of Law & Order and Law & Order: Special Victims Unit.

The data is here.

Makes me wonder if there is a archive of the soap operas that have been on for decades?

They survived because they have supporting audiences. Suspect a resource about the same would as well.

Named Entity Tutorial

Tuesday, May 21st, 2013

Named Entity Tutorial (LingPipe)

While looking for something else I ran across this named entity tutorial at LingPipe.

Other named entity tutorials that I should collect?

Preliminary evaluation of the CellFinder literature…

Friday, April 19th, 2013

Preliminary evaluation of the CellFinder literature curation pipeline for gene expression in kidney cells and anatomical parts by Mariana Neves, Alexander Damaschun, Nancy Mah, Fritz Lekschas, Stefanie Seltmann, Harald Stachelscheid, Jean-Fred Fontaine, Andreas Kurtz, and Ulf Leser. (Database (2013) 2013 : bat020 doi: 10.1093/database/bat020)

Abstract:

Biomedical literature curation is the process of automatically and/or manually deriving knowledge from scientific publications and recording it into specialized databases for structured delivery to users. It is a slow, error-prone, complex, costly and, yet, highly important task. Previous experiences have proven that text mining can assist in its many phases, especially, in triage of relevant documents and extraction of named entities and biological events. Here, we present the curation pipeline of the CellFinder database, a repository of cell research, which includes data derived from literature curation and microarrays to identify cell types, cell lines, organs and so forth, and especially patterns in gene expression. The curation pipeline is based on freely available tools in all text mining steps, as well as the manual validation of extracted data. Preliminary results are presented for a data set of 2376 full texts from which >4500 gene expression events in cell or anatomical part have been extracted. Validation of half of this data resulted in a precision of ∼50% of the extracted data, which indicates that we are on the right track with our pipeline for the proposed task. However, evaluation of the methods shows that there is still room for improvement in the named-entity recognition and that a larger and more robust corpus is needed to achieve a better performance for event extraction.

Database URL: http://www.cellfinder.org/.

Another extremely useful data curation project.

Do you get the impression that curation projects will continue to be outrun by data production?

And that will be the case, even with machine assistance?

Is there an alternative to falling further and further behind?

Such as abandoning some content (CNN?) to simply forever go uncurated? Or the same to be true for government documents/reports?

I am sure we all have different suggestions for what data to dump alongside the road to make room for the “important” stuff.

Suggestions on solutions other than simply dumping data?

A Survey of Stochastic and Gazetteer Based Approaches for Named Entity Recognition

Thursday, April 18th, 2013

A Survey of Stochastic and Gazetteer Based Approaches for Named Entity Recognition – Part 2 by Benjamin Bengfort.

From the post:

Generally speaking, the most effective named entity recognition systems can be categorized as rule-based, gazetteer and machine learning approaches. Within each of these approaches are a myriad of sub-approaches that combine to varying degrees each of these top-level categorizations. However, because of the research challenge posed by each approach, typically one or the other is focused on in the literature.

Rule-based systems utilize pattern-matching techniques in text as well as heuristics derived either from the morphology or the semantics of the input sequence. They are generally used as classifiers in machine-learning approaches, or as candidate taggers in gazetteers. Some applications can also make effective use of stand-alone rule-based systems, but they are prone to both overreach and skipping over named entities. Rule-based approaches are discussed in (10), (12), (13), and (14).

Gazetteer approaches make use of some external knowledge source to match chunks of the text via some dynamically constructed lexicon or gazette to the names and entities. Gazetteers also further provide a non-local model for resolving multiple names to the same entity. This approach requires either the hand crafting of name lexicons or some dynamic approach to obtaining a gazette from the corpus or another external source. However, gazette based approaches achieve better results for specific domains. Most of the research on this topic focuses on the expansion of the gazetteer to more dynamic lexicons, e.g. the use of Wikipedia or Twitter to construct the gazette. Gazette based approaches are discussed in (15), (16), and (17).

Stochastic approaches fare better across domains, and can perform predictive analysis on entities that are unknown in a gazette. These systems use statistical models and some form of feature identification to make predictions about named entities in text. They can further be supplemented with smoothing for universal coverage. Unfortunately these approaches require large amounts of annotated training data in order to be effective, and they don’t naturally provide a non-local model for entity resolution. Systems implemented with this approach are discussed in (7), (8), (4), (9), and (6).

Benjamin continues his excellent survey of named entity recognition techniques.

All of these techniques may prove to be useful in constructing topic maps from source materials.

An Introduction to Named Entity Recognition…

Wednesday, April 17th, 2013

An Introduction to Named Entity Recognition in Natural Language Processing – Part 1 by Benjamin Bengfort.

From the post:

Abstract:

The task of identifying proper names of people, organizations, locations, or other entities is a subtask of information extraction from natural language documents. This paper presents a survey of techniques and methodologies that are currently being explored to solve this difficult subtask. After a brief review of the challenges of the task, as well as a look at previous conventional approaches, the focus will shift to a comparison of stochastic and gazetteer based approaches. Several machine-learning approaches are identified and explored, as well as a discussion of knowledge acquisition relevant to recognition. This two-part white paper will show that applications that require named entity recognition will be served best by some combination of knowledge- based and non-deterministic approaches.

Introduction:

In school we were taught that a proper noun was “a specific person, place, or thing,” thus extending our definition from a concrete noun. Unfortunately, this seemingly simple mnemonic masks an extremely complex computational linguistic task—the extraction of named entities, e.g. persons, organizations, or locations from corpora (1). More formally, the task of Named Entity Recognition and Classification can be described as the identification of named entities in computer readable text via annotation with categorization tags for information extraction.

Not only is named entity recognition a subtask of information extraction, but it also plays a vital role in reference resolution, other types of disambiguation, and meaning representation in other natural language processing applications. Semantic parsers, part of speech taggers, and thematic meaning representations could all be extended with this type of tagging to provide better results. Other, NER-specific, applications abound including question and answer systems, automatic forwarding, textual entailment, and document and news searching. Even at a surface level, an understanding of the named entities involved in a document provides much richer analytical frameworks and cross-referencing.

Named entities have three top-level categorizations according to DARPA’s Message Understanding Conference: entity names, temporal expressions, and number expressions (2). Because the entity names category describes the unique identifiers of people, locations, geopolitical bodies, events, and organizations, these are usually referred to as named entities and as such, much of the literature discussed in this paper focuses solely on this categorization, although it is easy to imagine extending the proposed systems to cover the full MUC-7 task. Further, the CoNLL-2003 Shared Task, upon which the standard of evaluation for such systems is based, only evaluates the categorization of organizations, persons, locations, and miscellaneous named entities. For example:

(ORG S.E.C.) chief (PER Mary Shapiro) to leave (LOC Washington) in December.

This sentence contains three named entities that demonstrate many of the complications associated with named entity recognition. First, S.E.C. is an acronym for the Securities and Exchange Commission, which is an organization. The two words “Mary Shapiro” indicate a single person, and Washington, in this case, is a location and not a name. Note also that the token “chief” is not included in the person tag, although it very well could be. In this scenario, it is ambiguous if “S.E.C. chief Mary Shapiro” is a single named entity, or if multiple, nested tags would be required.

Nice introduction to the area and ends with a great set of references.

Looking forward to part 2!

Named entity extraction

Thursday, February 28th, 2013

Named entity extraction

From the webpage:

The techniques we discussed in the Cleanup and Reconciliation parts come in very handy when your data is already in a structured format. However, many fields (notoriously description) contain unstructured text, yet they usually convey a high amount of interesting information. To capture this in machine-processable format, named entity recognition can be used.

A Google Refine / OpenRefine extension developed by Multimedia Lab (ELIS — Ghent University / iMinds) and MasTIC (Université Libre de Bruxelles.

Described in: Named-Entity Recognition: A Gateway Drug for Cultural Heritage Collections to the Linked Data Cloud?

Abstract:

Unstructured metadata fields such as ‘description’ offer tremendous value for users to understand cultural heritage objects. However, this type of narrative information is of little direct use within a machine-readable context due to its unstructured nature. This paper explores the possibilities and limitations of Named-Entity Recognition (NER) to mine such unstructured metadata for meaningful concepts. These concepts can be used to leverage otherwise limited searching and browsing operations, but they can also play an important role to foster Digital Humanities research. In order to catalyze experimentation with NER, the paper proposes an evaluation of the performance of three thirdparty NER APIs through a comprehensive case study, based on the descriptive fields of the Smithsonian Cooper-Hewitt National Design Museum in New York. A manual analysis is performed of the precision, recall, and F-score of the concepts identified by the third party NER APIs. Based on the outcomes of the analysis, the conclusions present the added value of NER services, but also point out to the dangers of uncritically using NER, and by extension Linked Data principles, within the Digital Humanities. All metadata and tools used within the paper are freely available, making it possible for researchers and practitioners to repeat the methodology. By doing so, the paper offers a significant contribution towards understanding the value of NER for the Digital Humanities.

I commend the paper to you for a very close reading, particularly those of you in the humanities.

To conclude, the Digital Humanities need to launch a broader debate on how we can incorporate within our work the probabilistic character of tools such as NER services. Drucker eloquently states that ‘we use tools from disciplines whose epistemological foundations are at odds with, or even hostile to, the humanities. Positivistic, quantitative and reductive, these techniques preclude humanistic methods because of the very assumptions on which they are designed: that objects of knowledge can be understood as ahistorical and autonomous.’

Drucker, J. (2012), Debates in the Digital Humanities, Minesota Press, chapter Humanistic Theory and Digital Scholarship, pp. 85–95.

…that objects of knowledge can be understood as ahistorical and autonomous.

Certainly possible, but lossy, very lossy, in my view.

You?

A Consumer Electronics Named Entity Recognizer using NLTK [Post-Authoring ER?]

Saturday, December 1st, 2012

A Consumer Electronics Named Entity Recognizer using NLTK by Sujit Pal.

From the post:

Some time back, I came across a question someone asked about possible approaches to building a Named Entity Recognizer (NER) for the Consumer Electronics (CE) industry on LinkedIn’s Natural Language Processing People group. I had just finished reading the NLTK Book and had some ideas, but I wanted to test my understanding, so I decided to build one. This post describes this effort.

The approach is actually quite portable and not tied to NLTK and Python, you could, for example, build a Java/Scala based NER using components from OpenNLP and Weka using this approach. But NLTK provides all the components you need in one single package, and I wanted to get familiar with it, so I ended up using NLTK and Python.

The idea is that you take some Consumer Electronics text, mark the chunks (words/phrases) you think should be Named Entities, then train a (binary) classifier on it. Each word in the training set, along with some features such as its Part of Speech (POS), Shape, etc is a training input to the classifier. If the word is part of a CE Named Entity (NE) chunk, then its trained class is True otherwise it is False. You then use this classifier to predict the class (CE NE or not) of words in (previously unseen) text from the Consumer Electronics domain.

Should help with mining data for “entities” (read “subjects” in the topic map sense) for addition to your topic map.

I did puzzle over the suggestion for improvement that reads:

Another idea is to not do reference resolution during tagging, but instead postponing this to a second stage following entity recognition. That way, the references will be localized to the text under analysis, thus reducing false positives.

Post-authoring reference resolution might benefit from that approach.

But, if references were resolved by authors during the creation of a text, such as the insertion of Wikipedia references for entities, a different result would be obtained.

In those cases, assuming the author of a text is identified, they can be associated with a particular set of reference resolutions.

Prioritizing PubMed articles…

Wednesday, November 21st, 2012

Prioritizing PubMed articles for the Comparative Toxicogenomic Database utilizing semantic information by Sun Kim, Won Kim, Chih-Hsuan Wei, Zhiyong Lu and W. John Wilbur.

Abstract:

The Comparative Toxicogenomics Database (CTD) contains manually curated literature that describes chemical–gene interactions, chemical–disease relationships and gene–disease relationships. Finding articles containing this information is the first and an important step to assist manual curation efficiency. However, the complex nature of named entities and their relationships make it challenging to choose relevant articles. In this article, we introduce a machine learning framework for prioritizing CTD-relevant articles based on our prior system for the protein–protein interaction article classification task in BioCreative III. To address new challenges in the CTD task, we explore a new entity identification method for genes, chemicals and diseases. In addition, latent topics are analyzed and used as a feature type to overcome the small size of the training set. Applied to the BioCreative 2012 Triage dataset, our method achieved 0.8030 mean average precision (MAP) in the official runs, resulting in the top MAP system among participants. Integrated with PubTator, a Web interface for annotating biomedical literature, the proposed system also received a positive review from the CTD curation team.

An interesting summary of entity recognition issues in bioinformatics occurs in this article:

The second problem is that chemical and disease mentions should be identified along with gene mentions. Named entity recognition (NER) has been a main research topic for a long time in the biomedical text-mining community. The common strategy for NER is either to apply certain rules based on dictionaries and natural language processing techniques (5–7) or to apply machine learning approaches such as support vector machines (SVMs) and conditional random fields (8–10). However, most NER systems are class specific, i.e. they are designed to find only objects of one particular class or set of classes (11). This is natural because chemical, gene and disease names have specialized terminologies and complex naming conventions. In particular, gene names are difficult to detect because of synonyms, homonyms, abbreviations and ambiguities (12,13). Moreover, there are no specific rules of how to name a gene that are actually followed in practice (14). Chemicals have systematic naming conventions, but finding chemical names from text is still not easy because there are various ways to express chemicals (15,16). For example, they can be mentioned as IUPAC names, brand names, generic names or even molecular formulas. However, disease names in literature are more standardized (17) compared with gene and chemical names. Hence, using terminological resources such as Medical Subject Headings (MeSH) and Unified Medical Language System (UMLS) Metathesaurus help boost the identification performance (17,18). But, a major drawback of identifying disease names from text is that they often use general English terms.

Having a common representative for a group of identifiers for a single entity, should simplify the creation of mappings between entities.

Yes?

Unsupervised Named-Entity Recognition: Generating Gazetteers and Resolving Ambiguity

Sunday, June 3rd, 2012

Unsupervised Named-Entity Recognition: Generating Gazetteers and Resolving Ambiguity by David Nadeau, Peter D. Turney and Stan Matwin.

Abstract:

In this paper, we propose a named-entity recognition (NER) system that addresses two major limitations frequently discussed in the field. First, the system requires no human intervention such as manually labeling training data or creating gazetteers. Second, the system can handle more than the three classical named-entity types (person, location, and organization). We describe the system’s architecture and compare its performance with a supervised system. We experimentally evaluate the system on a standard corpus, with the three classical named-entity types, and also on a new corpus, with a new named-entity type (car brands).

The authors confide successful application of their techniques to more than 50 named-entity types.

They also recite heuristics that they apply to texts during the mining process.

Is there a common repository of observations or heuristics for mining texts? Just curious.

Source code for the project: http://balie.sourceforge.net.

Answer to the question I just posed?

A Resource-Based Method for Named Entity Extraction and Classification

Sunday, June 3rd, 2012

A Resource-Based Method for Named Entity Extraction and Classification by Pablo Gamallo and Marcos Garcia. (Lecture Notes in Computer Science, vol. 7026, Springer-Verlag, 610-623. ISNN: 0302-9743).

Abstract:

We propose a resource-based Named Entity Classification (NEC) system, which combines named entity extraction with simple language-independent heuristics. Large lists (gazetteers) of named entities are automatically extracted making use of semi-structured information from the Wikipedia, namely infoboxes and category trees. Language independent heuristics are used to disambiguate and classify entities that have been already identified (or recognized) in text. We compare the performance of our resource-based system with that of a supervised NEC module implemented for the FreeLing suite, which was the winner system in CoNLL-2002 competition. Experiments were performed over Portuguese text corpora taking into account several domains and genres.

Of particular interest if you are interested in adding NEC resources to the FreeLing project.

The introduction starts off:

Named Entity Recognition and Classification (NERC) is the process of identifying and classifying proper names of people, organizations, locations, and other Named Entities (NEs) within text.

Curious, what happens if you don’t have a “named” entity? That is an entity mentioned in the text but that doesn’t (yet) have a proper name?

Thinking of legal texts where some provision may apply to all corporations that engage in activity Y and that have a gross annual income in excess of amount X.

I may want to “recognize” that entity so I can then put a name with that entity.

FreeLing 3.0 – An Open Source Suite of Language Analyzers

Sunday, June 3rd, 2012

FreeLing 3.0 – An Open Source Suite of Language Analyzers

Features:

Main services offered by FreeLing library:

  • Text tokenization
  • Sentence splitting
  • Morphological analysis
  • Suffix treatment, retokenization of clitic pronouns
  • Flexible multiword recognition
  • Contraction splitting
  • Probabilistic prediction of unkown word categories
  • Named entity detection
  • Recognition of dates, numbers, ratios, currency, and physical magnitudes (speed, weight, temperature, density, etc.)
  • PoS tagging
  • Chart-based shallow parsing
  • Named entity classification
  • WordNet based sense annotation and disambiguation
  • Rule-based dependency parsing
  • Nominal correference resolution

[Not all features are supported for all languages, see Supported Languages.]

TOC for the user manual.

Something for your topic map authoring toolkit!

(Source: Jack Park)

Apache UIMA

Sunday, January 9th, 2011

Apache UIMA

From the website:

Unstructured Information Management applications are software systems that analyze large volumes of unstructured information in order to discover knowledge that is relevant to an end user. An example UIM application might ingest plain text and identify entities, such as persons, places, organizations; or relations, such as works-for or located-at.

UIMA enables applications to be decomposed into components, for example “language identification” => “language specific segmentation” => “sentence boundary detection” => “entity detection (person/place names etc.)”. Each component implements interfaces defined by the framework and provides self-describing metadata via XML descriptor files. The framework manages these components and the data flow between them. Components are written in Java or C++; the data that flows between components is designed for efficient mapping between these languages.

UIMA additionally provides capabilities to wrap components as network services, and can scale to very large volumes by replicating processing pipelines over a cluster of networked nodes.

The UIMA project offers a number of annotators that produce structured information from unstructured texts.

If you are using UIMA as a framework for development of topic maps, please post concerning your experiences with UIMA. What works, what doesn’t, etc.

Named Entity Mining from Click-Through Data Using Weakly Supervised Latent Dirichlet Allocation

Monday, December 20th, 2010

Named Entity Mining from Click-Through Data Using Weakly Supervised Latent Dirichlet Allocation (video) Authors: Shuang-Hong Yang, Gu Xu, Hang Li slides KDD ’09 paper

Abstract:

This paper addresses Named Entity Mining (NEM), in which we mine knowledge about named entities such as movies, games, and books from a huge amount of data. NEM is potentially useful in many applications including web search, online advertisement, and recommender system. There are three challenges for the task: finding suitable data source, coping with the ambiguities of named entity classes, and incorporating necessary human supervision into the mining process. This paper proposes conducting NEM by using click-through data collected at a web search engine, employing a topic model that generates the click-through data, and learning the topic model by weak supervision from humans. Specifically, it characterizes each named entity by its associated queries and URLs in the click-through data. It uses the topic model to resolve ambiguities of named entity classes by representing the classes as topics. It employs a method, referred to as Weakly Supervised Latent Dirichlet Allocation (WS-LDA), to accurately learn the topic model with partially labeled named entities. Experiments on a large scale click-through data containing over 1.5 billion query-URL pairs show that the proposed approach can conduct very accurate NEM and significantly outperforms the baseline.

With some slight modifications, almost directly applicable to the construction of topic maps.

Questions:

  1. What presumptions underlie the use of supervision to assist with Named Entity Mining? (2-3 pages, no citations)
  2. Are those valid presumptions for click-through data? (2-3 pages, no citations)
  3. How would you suggest investigating the characteristics of click-through data? (2-3 pages, no citations)