dialogue system development pontus johansson [email protected] nlplab, linköping university

Dialogue System Development

Pontus [email protected]

NLPLAB, Linköping University

GSLT - Dialogue Systems 2 2 030128

Outline

Iterative Dialogue System Development NlpFarm: A Development Environment

Iterative Development


Problems With DS Development

Overhead of extensive planning Overhead of ’monolithic’ architectures Knowing what to do and how?? Our approach:

Iterative method


Iterative Method

Design and implementation in parallel Takes stock of resources Clear development space Incremental development of functionality Minimize planning of work that turns out to

be unnecessary…


Method Overview

DS design

DS module

DS theory DS requirements specification

Other modulesDS framework

Con

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ion


Development Space

Tools

Code patterns

Modularisatio

n

Interface

s

Knowledge

representatio

n

Frameworktemplates

Dialogue history

Atomic request handling

Sub-dialogue controlX

X

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X

X

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X X

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DS FrameworkCustomisation

DS Design

DS Capabilities


Applying the Iterative method Iteration 1: Q/A-system

Iteration 2: Dialogue history

Iteration 3: Sub-dialogue

Q/A:U: List actors in Star WarsS: [Marc Hamill, Harrison Ford, …]U: Who directed Star Wars?S: George Lucas

Dialogue history:U: Who is starring in the Bond movie?S: Sean ConneryU: And who directed it?S: Guy Hamilton

Sub-dialogue:U: Show all movies todayS: There are 30 shows that matches. Do you wish to see them all?U: Nah, only the ones after nine pmS: [TABLE]


Resources

Lars Degerstedt and Arne Jönsson. A Method for Iterative Implementation of Dialogue Management. IJCAI Workshop on Knowledge and Reasoning in Practical Dialogue Systems, Seattle, 2001.

Lars Degerstedt and Arne Jönsson. Iterative Implementation of Dialogue System Modules. Proceedings of Eurospeech 2001. Aalborg, Denmark, 2001.

Pontus Johansson, Lars Degerstedt and Arne Jönsson. Iterative Development of an Information-Providing Dialogue System. Proceedings of the 7th ERCIM Workshop "User Interfaces for All”. Paris, France, 2002.

NlpFarm


Aims and Motivation

Contribute to an open source framework for NLP.

Aims at being a channel for research results to transform into working software.Library and framework codeRunning systems and demos


Aims and Motivation

The nlpFarm is open to anyone and will in particular: host various demo systems showing the strength of NLP

software. be a channel for student projects (both undergraduate and

graduate) to distribute their results. facilitate the administrative overhead for such projects by reuse

from earlier efforts. be the home site for tools and frameworks developed under

longer time periods in various research projects. be a host for NLP applications based on NLP research software. be a channel for industrial partners and other interesting parties

to download and try out existing NLP research resources.


Tool example: JavaChart

Chartparser written in Java Stand-alone (command line interface) Or, as part of e.g. a dialogue system Uses the Feature Structure package of the

nlpLib Java library.


Library example: nlpLib

Includes utilities such as:Unifiable Feature StructuresPhased Language Process (PLP) design

patternLibrary for text generation

The PLP pattern suits the iterative method


Phased Language Processing (PLP)


Phased Language Processing (PLP)

+ Decoupling control code+ Easy addition and removal of phases+ Providing a unified API for the process control of

the system+ Low overhead in design and implementation

- The Phase Graph can be too complex- Use of the state as the only transfer of data can

become a bottle-neck


Iterations and Increments

Two incremental iterations Iteration 1 re-uses design from TvGuide Iteration 2 consists of adding phases from BirdQuest and refactoring

the system to be able to merge and refine the newly added phases with those from increment 1.

The final design of increment 2 thereby gets a pure phase design.


Re-using libs and tools

Design a simple set of phases (PLP pattern in nlpLib library) for a Q/A (first iteration)

1. Parse Phase2. Database Access Phase3. Generation Phase

Use JavaChart tool for parse phase Use Quaks framework for DB access phase Use nlpLib.tgen library for generation phase (see BirdQ and TvGuide demos)


Implementing a simple PLP

ParsePhase AccessPhase GenerationPhase

The 3 phases are ordered in a ”pure phase graph”

IN OUT


Implementing a simple PLP

package tvguide.process;

import opennlp.nlplib.plp.*;

public class TvGuidePlp { PhaseProcessor pp;

public TvGuidePlp() { ParsePhase p1 = new ParsePhase(); AccessPhase p2 = new AccessPhase(); GenerationPhase p3 = new GenerationPhase(); Phase[] ordering = {p1, p2, p3}; PurePhaseGraph graph = new PurePhaseGraph(ordering); this.pp = new PhaseProcessor(graph); }//constructor…


Configuring the ParsePhase

Create a class ParserClient, which communicates with JavaChart Simple method parse:

public FeatureStructure parse(String userInput) {Map m = jc.parse(userInput.trim()); //jc is the JavaChart ”server”List l = (List) m.get("s"); //s is top category in grammarif (!l.isEmpty()) { return (FeatureStructure) l.get(0); //FeatureStructure is part of nlpLib} else { return null;}

}


Using Quaks for DB Queries

opennlp.Quaks.access: support for access sessions against a KS. Currently (0.1.0) supports: MySql "ordinary" URL sources

opennlp.Quaks.query: support for building queries for database resources. Supported: MySql.

opennlp.Quaks.template: Contains a Controller-holder pattern for query template handling. Implements a generic so-called access carrier for template-based access using the access package.


Using Quaks for DB Queries

BirdQ uses MySql queries TvGuide uses URL queries (Internet Movie

Database)


tGen for Text Generation

BirdQ demo shows how to use opennlp.nlplib.tgen for text generation


Resources

NlpFarm home pagehttp://nlpfarm.sourceforge.net/

NlpFarm projects:http://nlpfarm.sourceforge.net/projects.html

Sourceforgehttp://sourceforge.net/projects/nlpfarm

dialogue system development pontus johansson [email protected] nlplab, linköping university

Documents

gslt dialogue systems

practical dialogue systems

iterative development

dialogue history iteration

subdialogue qa

nlpfarm slide

development environment

george lucas dialogue