An Adaptation Technique for GF-Based Dialogue Systems Faegheh - - PowerPoint PPT Presentation

▶
an adaptation technique for gf based dialogue systems
SMART_READER_LITE
LIVE PREVIEW

An Adaptation Technique for GF-Based Dialogue Systems Faegheh - - PowerPoint PPT Presentation

Apr 17, 2023 41 likes •349 views

An Adaptation Technique for GF-Based Dialogue Systems Faegheh Hasibi August 31, 2012 Department of Computer Science and Engineering Chalmers University of Technology and University of Gothenburg Outline Introduction The Baseline System

slide-1
SLIDE 1

An Adaptation Technique for GF-Based Dialogue Systems

Faegheh Hasibi August 31, 2012

Department of Computer Science and Engineering Chalmers University of Technology and University of Gothenburg

slide-2
SLIDE 2

Outline

  • Introduction
  • The Baseline System
  • Adaptation Technique
  • Example: An Adaptable Transport Query System
  • Evaluation
  • Directions

August 31, 2012 2 Chalmers - University of Gothenburg

slide-3
SLIDE 3

Introduction

Examples in a transport dialogue system:

  • Normal dialogue:

User: I want to go from Chalmers to Valand today at 7:30 System: Take tram number 7 from Chalmers to Valand at 7:33

  • User adaptable dialogue:

User: work means Chalmers on Monday at 7:30 User: home means Valand

User: I want to go from work to home System: Take tram number 7 from Chalmers to Valand at 7:33

August 31, 2012 Chalmers - University of Gothenburg 3

slide-4
SLIDE 4

Objective

  • To adapt the GF grammar of information-seeking

dialogue systems

August 31, 2012 4 Chalmers - University of Gothenburg

Database Lexicon Grammar

slide-5
SLIDE 5

Grammatical Framework (GF)

  • GF is a multilingual grammar formalism.
  • Translate phrases between several languages.
  • GF grammars are divided to two module types:

– Abstract module – The ontology of a domain – Concrete module – Linearization of a abstract syntax in a particular language

June 11, 2012 Chalmers - University of Gothenburg 5

slide-6
SLIDE 6

Portable Grammar Format (PGF)

  • PGFs are generated by compiling a set of concrete

grammars with the same abstract syntax.

  • PGF is a low-level binary format of GF grammars
  • A PGF interpreter is needed to work with PGF files

– performs parsing, linearization, random generation and type checking

August 31, 2012 6 Chalmers - University of Gothenburg

slide-7
SLIDE 7

The transport query system

Features:

  • Multilingual GF-based query system

– English and Swedish languages

  • Presents up-to-date travel plan

– Communicates with a transport web service

  • Can be used for other transport networks

– Stop names are automatically added to the grammar by the GF Writer application

August 31, 2012 Chalmers - University of Gothenburg 7

slide-8
SLIDE 8

GF Writer Application

The embedded GF writer:

  • Writes GF grammar rules during the execution of a

program

  • Generates or modifies abstract and concrete GF

modules

  • Compiles GF grammars and generates PGF files

– Run GF software commands

August 31, 2012 Chalmers - University of Gothenburg 8

slide-9
SLIDE 9

System Overview

August 31, 2012 Chalmers - University of Gothenburg 9

slide-10
SLIDE 10

Grammar overview

  • Natural language grammars and HTTP grammar

have the same abstract syntax

  • Mapping between natural language queries and

HTTP requests

August 31, 2012 Chalmers - University of Gothenburg 10

Abstract Syntax

English HTTP Swedish

slide-11
SLIDE 11

Grammar Structure

  • Separate modules for query and

answer utterances

  • Stop grammar holds stop names

and identifiers

  • Stop names can be offered to

users

August 31, 2012 11 Chalmers - University of Gothenburg

slide-12
SLIDE 12

Stop Grammar

  • Abstract Syntax

fun St_1 : Stop;

  • English linearization

lin St_1 = mkStop " Valand " "Göteborg" "track A";

  • per

mkStop : Str -> Str -> Str -> TStop = \stop, region, track -> { s = stop; r = region; t = track; alt = stop ++ region};

  • HTTP linearization

lin St_1 = {s = "9022014004420003"};

August 31, 2012 12 Chalmers - University of Gothenburg

slide-13
SLIDE 13

Query Grammar

  • Abstract Syntax

fun GoFromTo : Stop -> Stop -> Day -> Time -> Query ;

  • HTTP linearization

lin GoFromTo from to day time = {s = "date=“ ++ day.s ++ "&time=" ++ time.s ++ "&originId=" ++ from.s ++ "&destId=" ++ to.s};

August 31, 2012 13 Chalmers - University of Gothenburg

slide-14
SLIDE 14

Adaptation Challenges in GF

  • GF grammar adaptation can be costly in 2 aspects:

1. Modifying GF modules

  • pening a GF module
  • Searching through rule

2. Reproducing the PGF file

  • Adaptation can be even worse when:

– Changes need to be applied for several modules – GF modules are huge

August 31, 2012 14 Chalmers - University of Gothenburg

slide-15
SLIDE 15

Adaptation Technique

  • Changes are applied to an extension grammar
  • The Extenxion grammar extends all other grammars
  • New grammar rules will be added gradually

August 31, 2012 Chalmers - University of Gothenburg 15

slide-16
SLIDE 16

Adaptation Technique

Grammar Compilation:

  • GF compiles grammars separately
  • The only compiled grammar is the Extension grammar

– The huge main grammar is not compiled

  • The compilation time is short

August 31, 2012 16 Chalmers - University of Gothenburg

slide-17
SLIDE 17

Adaptable Travel Grammar

  • Convert the query system to an

adaptive one

  • The adaptation technique is

used for:

  • 1. User adaptation
  • 2. Self-adaptation

August 31, 2012 Chalmers - University of Gothenburg 17

DayTime Answer Travel Query Stop Ext Def

slide-18
SLIDE 18
  • 1. User Adaptation

Stop, Day and Time Customization:

  • User definition: Work means Chalmers on Monday at 7:30
  • Abstract syntax tree:

(Customize ((((DefPlaceDayTime Work) St_2) Monday) ((HourMin (Num N7)) ((Nums N3) (Num N0)))))

August 31, 2012 18 Chalmers - University of Gothenburg

slide-19
SLIDE 19
  • 1. User Adaptation

Stop, Day and Time Customization:

Abstract syntax:

abstract Ext = Travel ** { fun WorkStopDayTime : StopDayTime; }

August 31, 2012 19 Chalmers - University of Gothenburg

slide-20
SLIDE 20
  • 1. User Adaptation

Stop, Day and Time Customization:

English concrete syntax:

lin WorkStopDayTime = toStopDayTime TravelEng.Work TravelEng.St_2 TravelEng.Monday "7:30";

  • per

toStopDayTime: {s : Str} -> Stop -> Day -> Str -> StopDayTime = \new, s, d, t -> {stop = s; day= d; time= t; alt = new.s};

August 31, 2012 20 Chalmers - University of Gothenburg

slide-21
SLIDE 21
  • 1. User Adaptation

Stop, Day and Time Customization:

HTTP concrete syntax:

lincat StopDayTime = {stop : Stop; day : Day; time : Str}; lin WorkStopDayTime = toStopDayTime TravelEng.St_2 TravelEng.Monday "7:30";

  • per

toStopDayTime : Stop -> Day -> Str -> StopDayTime = \st, d, t -> { stop = st; day = d; time = t };

August 31, 2012 21 Chalmers - University of Gothenburg

slide-22
SLIDE 22
  • 1. User Adaptation

Stop customization:

  • User definition: Home means Valand.

Abstract syntax: No changes Concrete syntax:

concrete ExtEng of Ext = TravelEng - [ St_1 ] ** { lin St_1 = toStop TravelEng.Home TravelEng.St_1; } toStop : {s : Str} -> Stop -> Stop = \new, stop -> {s = stop.s; r = stop.r; t = stop.t; alt = stop.alt | new.s};

August 31, 2012 22 Chalmers - University of Gothenburg

slide-23
SLIDE 23
  • 2. Self-adaptation
  • Keep the system always updated

– Adding new vehicle labels

Steps:

  • Check the label is exists in the grammar

– Try to parse the label

  • If the parser does not succeeds

– A new rule will be added

August 31, 2012 Chalmers - University of Gothenburg 23

slide-24
SLIDE 24
  • 2. Self-adaptation

Abstract syntax:

abstract Ext = Travel ** { fun Lbl_new : Label; . . . }

Concrete syntax:

concrete ExtEng of Ext = TravelEng-[ . . . ]** { lin Lbl_new = { s=“Grön Express”}; . . . }

August 31, 2012 Chalmers - University of Gothenburg 24

slide-25
SLIDE 25

Adaptable Transport Query System

  • Supported format for user’s definitions:

– value means stop-name – value means stop-name day – value means stop-name day time – value means day

  • The changes are applied to all supported languages

while adapting the system in one language.

August 31, 2012 Chalmers - University of Gothenburg 25

slide-26
SLIDE 26

Evaluation

The effect of user adaptation on speech recognition was assessed:

– 120 random generated queries were fed to an ordinary speech recognizer (Google)

  • All non-adapted queries were failed.
  • Most of the adapted queries were passed.

August 31, 2012 26 Chalmers - University of Gothenburg

slide-27
SLIDE 27

Evaluation (Non-adapted queries)

A failed non-adapted query:

 I want to go from Skra Bro to Vrångö on Tuesday at 13:12  I want to go from scratch the tools call on Tuesday at 13:12

Speech recognizer behavior :

– Can find known words – Cannot recognize foreign words by guessing alphabets – Translate foreign words to known words

August 31, 2012 27 Chalmers - University of Gothenburg

slide-28
SLIDE 28

Evaluation (Adapted queries)

A failed adapted query:

 I want to go from pub to park on Friday at 15:35  I want to go from park to park on Friday at 15:35

Speech recognition is improved by adaptation:

– Elimination of foreign words – Shorter queries

August 31, 2012 28 Chalmers - University of Gothenburg

slide-29
SLIDE 29

Evaluation (Error rate)

  • Word error rate:

Rate of un-recognized words in a sentence – each query and the recognized one was checked word by word.

  • Sentence error rate:

Rate of failure in recognizing the whole sentence correctly

August 31, 2012 29 Chalmers - University of Gothenburg

Word error rate Sentence error rate Non-adapted queris 58% 100% Adapted queries 26% 53%

slide-30
SLIDE 30

Directions

  • Extend the transport query system to a multimodal

system (to support speech, text and map clicks).

  • Use more efficient algorithm for searching through a

GF module

  • Apply the adaptation to various domains

– Media players – Price comparison services

August 31, 2012 30 Chalmers - University of Gothenburg