jacana-freebase is a question answering engine that extracts answers from [http://www.freebase.com Freebase], given a short factoid web-style question (just as the one you type into a search engine), such as who did natalie portman play in star wars?
jacana-freebase is very "researchy" code with a GPLv3 license. It runs in batch mode with a bunch of scripts. Currently there is no plan to engineer it into a real-time QA engine. Underlying algorithm and evaluation result can be found at:
Information Extraction over Structured Data: Question Answering with Freebase. Xuchen Yao and Benjamin Van Durme. Proceedings of ACL 2014.
jacana-freebase is written in a mixture of Java and Scala. If you build from ant, you have to set up the environmental variables JAVA_HOME and SCALA_HOME. In my system, I have:
export JAVA_HOME=/usr/lib/jvm/java-6-sun-1.6.0.26
export SCALA_HOME=/home/xuchen/Downloads/scala-2.10.3
Then type:
ant -f build.freebase.xml
An all-in-one jar file, build/lib/jacana-freebase.jar, will be built for you.
If you build from Eclipse, first install [http://scala-ide.org/ scala-ide], then import the whole jacana folder as a Scala project. Eclipse should find the .project file and set up the project automatically for you.
The training/testing pipeline:
Given training/test files, run edu.jhu.jacana.freebase.featureextraction.GraphFeatureWriter to extract features, and save in .bnf files
run a high performance trainer/classifier, [http://www.chokkan.org/software/classias/ Classias], to train the model, and tag the test file.
The script scripts-freebase/extractFeaturesGraph.sh reproduces the above pipeline. To run the code, you need to:
- pass the JACANA_HOME variable to java through
-DJACANA_HOME=/folder/to/jacanawhere it points to the parent folder ofscripts-freebase. - pass the FREEBASE_DATA variable to java through
-DFREEBASE_DATA=/folder/to/freebase-datawhere you should download additional data from here: [http://cs.jhu.edu/~xuchen/packages/freebase-data.tar freebase-data.tar (3.3GB)] - have [http://www.chokkan.org/software/classias/ Classias] installed.