Relation Extraction

Introduction

A relation is a relationship between a pair of entity mentions. Currently we only detect relation pairs within the same sentence. There are often many relations within a sentence. For example, In sentence

Coalition forces in Iraq have captured a member of a terrorist group with links to al Qaeda .

There are the following relations:

Located_In([forces], [Iraq])
Employment([Coalition], [forces])
Membership([member], [terrorist group])
Affiliation([terrorist group], [al Qaeda])

Knowing these relations is helpful for many tasks in NLP.

This application uses Mention Detection to identify mentions first, and uses a model trained with supervised learning and feature engineering on ACE2005 data to identify relations among the mentions detected. Since the model is built on ACE2005, the model identifes the following types:

Coarse Type	Fine Type
PHYS	Located,Near
PART-WHOLE	Geographical,Subsidiary,Artifact
PER-SOC	Lasting-Personal,Business,Family
ORG-AFF	Employment,Ownership,Founder,Student-Alum,Sports-Affiliation,Investor-Shareholder,Membership
ART	User-Owner-Inventor-Manufacturer
GEN-AFF	Citizen-Resident-Religion-Ethnicity,Org-Location

Results

We test results on both Coarse Type and Fine Type, and on both gold mention data (i.e. the mentions are given) and predicted mention data (i.e. use MD to detect mentions).

	Coarse Type	Fine Type
Gold Mention	58.35	62.54
Predicted Mention	44.07	41.90

We also provides results tested on SemEval-2008 dataset. The task defined in this set is slightly different and the classifier is not feature engineered for this dataset.

	Precision	Recall	F1
SemEval2008	78.04	82.59	80.25

Usage

Install with Maven

If you want to use the illinois-relation-extraction package independently, you can add a maven dependency in your pom.xml. Please replace the VERSION with the latest version of the parent package.

<dependency>
    <groupId>edu.illinois.cs.cogcomp</groupId>
    <artifactId>illinois-relation-extraction</artifactId>
    <version>VERSION</version>
</dependency>

Using Annotator

Using the annotator RelationAnnotator() is the preferred and the easiest way to use relation extraction package. This annotator annotates mentions, and then annotate relations. If you have a pre-defined mention set, please refer to Using Relation Classifier Only

Using the annotator is easy.

import edu.illinois.cs.cogcomp.annotation.TextAnnotationBuilder;
import edu.illinois.cs.cogcomp.core.datastructures.ViewNames;
import edu.illinois.cs.cogcomp.core.datastructures.textannotation.Constituent;
import edu.illinois.cs.cogcomp.core.datastructures.textannotation.Relation;
import edu.illinois.cs.cogcomp.core.datastructures.textannotation.TextAnnotation;
import edu.illinois.cs.cogcomp.core.datastructures.textannotation.View;
import edu.illinois.cs.cogcomp.nlp.tokenizer.StatefulTokenizer;
import edu.illinois.cs.cogcomp.nlp.utility.TokenizerTextAnnotationBuilder;
import java.util.List;
import java.io.IOException;
import java.util.List;

public class app
{
    public static void main( String[] args ) throws IOException, AnnotatorException
    {
        String text = "He went to Chicago after his Father moved there.";

        String corpus = "story";
        String textId = "001";

        // Create a TextAnnotation From Text
        TextAnnotationBuilder stab =
                new TokenizerTextAnnotationBuilder(new StatefulTokenizer());
        TextAnnotation ta = stab.createTextAnnotation(corpus, textId, text);

        //Use Annotators or pipeline to annotate required Views:
        //POS, SHALLOW_PARSE, DEPENDENCY_STANFORD

        RelationAnnotator relationAnnotator = new RelationAnnotator();
        try {
            relationAnnotator.addView(ta);
        }
        catch (Exception e){
            e.printStackTrace();
        }

        View mentionView = ta.getView(ViewNames.MENTION);

        List<Constituent> predictedMentions = mentionView.getConstituents();
        List<Relation> predictedRelations = mentionView.getRelations();

        for (Relation r : predictedRelations){
            IOHelper.printRelation(r);
        }
    }
}

As the sample indicates, the annotator annotates the view ViewNames.MENTION, which contains both predicted mentions and predicted relations. Please refer to the structure of Relation.

For a full version of this demo, please refer to AnnotatorExample

Using Relation Classifier Only

Please refer to the inner implementation of addView() in RelationAnnotator to see how to do this.

Classify SemEval Relations

Please refer to ExampleUsage

Run Tests

Data Pre-process

There is a handy IOHelper class which pre-annotates a large corpus and save them into single files.

Custom training/testing

Please refer to the three tests placed in ACERelationTester to see how to train models.

Citation

If you use this tool, please cite the following works.

@inproceedings{ChanRo10,
    author = {Y. Chan and D. Roth},
    title = {Exploiting Background Knowledge for Relation Extraction},
    booktitle = {COLING},
    month = {8},
    year = {2010},
    address = {Beijing, China},
    url = "http://cogcomp.org/papers/ChanRo10.pdf",
    funding = {MR},
    projects = {NLP, IE},
    comment = {Relation extraction, background knowledge, constraints, information extraction},
}
@inproceedings{ChanRo11,
    author = {Y. Chan and D. Roth},
    title = {Exploiting Syntactico-Semantic Structures for Relation Extraction},
    booktitle = {ACL},
    year = {2011},
    address = {Portland, Oregon},
    url = "http://cogcomp.org/papers/ChanRo11.pdf",
    funding = {MR},
    projects = {NLP, IE},
}