Open IE

This project contains the principal Open Information Extraction (Open IE) system from the University of Washington (UW). An Open IE system runs over sentences and creates extractions that represent relations in text. For example, consider the following sentence.

The U.S. president Barack Obama gave his speech on Tuesday to thousands of people.

There are many binary relations in this sentence that can be expressed as a triple (A, B, C) where A and B are arguments, and C is the relation between those arguments. Since Open IE is not aligned with an ontology, the relation is a phrase of text. Here is a possible list of the binary relations in the above sentence:

(Barack Obama, is the president of, the U.S.)
(Barack Obama, gave, his speech)
(Barack Obama, gave his speech, on Tuesday)
(Barack Obama, gave his speech, to thousands of people)

The first extraction in the above list is a "noun-mediated extraction", because the extraction has a relation phrase is described by the noun "president". The other extractions are very similar. In fact, they can be represented more informatively as an n-ary extraction. An n-ary extraction can have 0 or more secondary arguments. Here is a possible list of the n-ary relations in the sentence:

(Barack Obama, is the president of, the U.S.)
(Barack Obama, gave, [his speech, on Tuesday, to thousands of people])

Extractions can include more than just the arguments and relation as well. For example, we might be interested in whether the extraction is a negative assertion or a positive assertion, or if it is conditional in some way. Consider the following sentence:

Some people say Barack Obama was born in Kenya.

We would not want to extract that (Barack Obama, was born, in Kenya) alone because this is not true. However, if we have the condition as well, we can have a correct extraction.

Some people say:(Barack Obama, was born in, Kenya)

To see an example of Open IE being used, please visit http://openie.cs.washington.edu/.

Notifications

• June 2016

This repository is a modification of https://github.com/knowitall/openie at 9dcbf4b0a4fd088d780a3f4480ce9ce811295f30 to run on Scala 2.11.

This project currently has many dependencies that would need to migrate to Scala 2.11. To make the migration and future maintenence easier, @schmmd copied in the dependent libraries:

• Common-scala
• NLP Tools
• ChunkedExtractor
• Srlie

In addition, some code has been removed to ease migration to Scala 2.11:

• https://github.com/allenai/openie-standalone/commit/6b4c22ed6a7779c95042e103d4e4975167b7bf55

Finally, ClearSrl.scala was adjusted to produce consistent behavior in Scala 2.11:

• https://github.com/allenai/openie-standalone/commit/bb5cf227448d2bf077146899c537d72fd8a228f0

• [01/15/2016] The version 4.2.0 is released (release notes).

Google Group

• knowitall_openie

Research

Open IE 4.x is the successor to Ollie. Whereas Ollie used bootstrapped dependency parse paths to extract relations (see Open Language Learning for Information Extraction), Open IE 4.x uses similar argument and relation expansion heuristics to create Open IE extractions from SRL frames. Open IE 4.x also extends the defintion of Open IE extractions to include n-ary extractions (extractions with 0 or more arguments 2s).

Buiding

openie uses java-7-openjdk & the sbt build system, so downloading dependencies and compiling is simple. Just run:

sbt compile

Memory requirements

openie requires substantial memory. sbt is configured to use these options by default:

-Xmx4G -XX:+UseConcMarkSweepGC

Usage

Command Line Interface

Check out this project and use sbt to run the CLI:

% git clone [email protected]:allenai/openie-standalone.git
% cd openie-standalone
% sbt "runMain edu.knowitall.openie.OpenIECli"
...
[info] * * * * * * * * * * * * *
[info] * OpenIE 4.1.x is ready *
[info] * * * * * * * * * * * * *

openie takes a number of command line arguments. To see them all run sbt "runMain edu.knowitall.openie.OpenIECli --usage". Of particular interest are --ignore-errors which continues running even if an exception is encountered, --binary which gives the binary(triples) output and --split which splits the input document text into sentences.

There are two output formats in the CLI: a simple format made for ease of reading and a columnated format used for machine processing. The format can be specified with either --format simple or --format column. The simple format is chosen by default.

Code interface

You can depend on the OpenIE library in your SBT-based application instead of using the CLI. The minimal declaration in your build.sbt file is:

resolvers += Resolver.jcenterRepo
libraryDependencies += "org.allenai.openie" %% "openie" % "4.2.6"

Hello World example

To illustrate how OpenIE can be done used in your application, here is a Hello World application.

Make a new directory and create three files:

File 1: build.properties:

sbt.version=0.13.11

File 2: build.sbt:

scalaVersion := "2.11.8"
resolvers += Resolver.jcenterRepo
libraryDependencies += "org.allenai.openie" %% "openie" % "4.2.6"

File 3: OpenIEHelloWorld.scala:

import edu.knowitall.openie.OpenIE
import edu.knowitall.openie.OpenIECli.{ColumnFormat, SimpleFormat}
import java.io.{PrintWriter, StringWriter}

object OpenIEHelloWorld {
    val openie = new OpenIE
    val sentence = "U.S. President Obama gave a speech"
    val instances = openie.extract(sentence)

    def main(args: Array[String]): Unit = {
        println("Hello, OpenIE world.")
        exampleUsage1()
        exampleUsage2()
        exampleUsage3()
    }

    def exampleUsage1() : Unit = {
        println("Example Usage 1:")
        println("")
        var s = new StringBuilder()
        for (instance <- instances) {
          s.append("Instance: " + instance.toString() + "\n")
        }
        println(s.toString())
    }

    def exampleUsage2() : Unit = {
        println("Example Usage 2:")
        println("")
        val sw = new StringWriter()
        SimpleFormat.print(new PrintWriter(sw), sentence, instances)
        println(sw.toString())
    }

    def exampleUsage3() : Unit = {
        println("Example Usage 3:")
        println("")
        val sw = new StringWriter()
        ColumnFormat.print(new PrintWriter(sw), sentence, instances)
        println(sw.toString())
    }

}

In this example, openie.extract(...) is used. It returns a sequence of Instance objects, which are containers for extractions and confidences. Each extraction has various fields you can access manually. These fields are used directly (.toString), with SimpleFormat and with ColumnFormat.

Finally, run the application with sbt -J-Xmx4G run to see output like this:

Hello, OpenIE world.
Example Usage 1:

Instance: 0.93 (U.S. President Obama; gave; a speech)
Instance: 0.88 (Obama; [is] President [of]; United States)

Example Usage 2:

U.S. President Obama gave a speech
0.93 (U.S. President Obama; gave; a speech)
0.88 (Obama; [is] President [of]; United States)


Example Usage 3:

0.9329286852051247     		SimpleArgument(U.S. President Obama,List([0, 20)))     	Relation(gave,List([21, 25)))  	SimpleArgument(a speech,List([26, 34)))	U.S. President Obama gave a speech
0.8847999636040884     		SimpleArgument(Obama,List([15, 20)))   	Relation([is] President [of],List([5, 14)))    	SimpleArgument(United States,List([0, 4)))     	U.S. President Obama gave a speech

Contributors

• Michael Schmitz (http://www.schmitztech.com/)
• Harinder Pal (http://www.cse.iitd.ac.in/~mcs142123/)
• Bhadra Mani
• Michal Guerquin