This repository contains code (service and demo) for the paper and demo titled "Unsupervised Discovery of Corroborative Paths for FactValidation" and "COPAAL – An Interface for Explaining Facts usingCorroborative Paths" respectively, accepted at International Semantic Web Conference (ISWC-2019).
COPAAL is an unsupervised fact validation approach for RDF knowledge graphs which identifies paths that support a given fact (s,p,o). This approach is based on the insight that the predicate p (e.g.,nationality) carries mutual information with a set of other paths (e.g., paths pertaining to birthPlace and country) in the background knowledge graph G. Hence,the presence of certain sets of paths in G that begin in s and end in o can be regarded as evidence which corroborates the veracity of (s,p,o). For example, we would have good reasons to believe that BarackObama is a citizen of the USA given that BarackObama was born in Hawaii and Hawaii is located in the USA (see figure below).
COPAAL uses infomation from a given background knowledge graph G hosted on a sparql end-point. Currently, COPAAL supports knowledge graphs that contains ontology information. An example of a KG that defines type information is DBpedia. In our experiments, we used DBpedia and the usage instructions are for the same.
- Prepare a sparql end-point of your choice and index the following dumps of DBpedia version 10-2016:
ontology,instance types,mapping-based objectsandinfobox properties. - Clone the repository from https://github.com/dice-group/COPAAL. The repository contains two components namely the service and demo (ui-service).
To use the service do the following:
- Update the URL to map to your sparql end-point (from previous step) in https://github.com/dice-group/COPAAL/blob/master/service/src/main/resources/application.properties
- COPAAL is developed using Spring Boot Maven.
- Build the project by navigating to service folder and issuing the the command
mvn clean install.
- using IDE
- packaged application
- using maven plugin
You can run COPAAL service from your IDE as a simple Java application. To do this simply import the maven project in your IDE of choice and run https://github.com/dice-group/COPAAL/blob/master/service/src/main/java/org/dice/FactCheck/Application.java.
To run COPAAL as packaged application, open a terminal and navigate to the target sub-directory inside service folder. Issue the command java -jar Corraborative-0.0.1-SNAPSHOT.jar
The Spring Boot Maven plugin includes a run goal that can be used to quickly compile and run applications. To run COPAAL service using this option, navigate to the service folder and issue the command mvn spring-boot:run.
Using one or more options above, COPAAL service will be deployed. The running service can be verified by issuing the following example GET request from a browser
In addition to the COPAAL service, one can deploy a UI-service in order to query and validate facts using a web interface. The demo was developed using Angular CLI version 7.0.3.
To build the demo navigate to the ui-service folder and run ng build. The build artifacts will be stored in the dist/ directory.
Run ng serve to deploy the demo. To use the demo navigate to http://localhost:4200/. You should see the web-page as shown in the figure below.
