Language Model as an Annotator: Exploring DialoGPT for Dialogue Summarization

Xiachong Feng1, Xiaocheng Feng1,2, Libo Qin1, Bing Qin1,2, Ting Liu1,2

1 Harbin Institute of Technology, 2 Peng Cheng Laboratory

Dialogue Summarization• Dialoguesummarizationaimstogenerateasuccinctsummarywhileretainingessentialinformationofthedialogue.

2

Remember we are seeing the wedding planner after workSure, where are we meeting her? At Nonna Rita’s I want to order seafood tagliatelle Haha why notWe remmber spaghetti pomodoro disaster from our last meetingOmg it was over her white blouse:D:P

Blair and Chuck are going to meet the wedding planner after work at Nonna Rita’s. The tagliatelle served at Nonna Rita’s are very good.

Blair:

Chuck:Blair:Chuck: Blair:Chuck:

Blair:Chuck:Blair:

Dialogue

Summary

A Good Summary?

3

Informativeness Redundancy Relevance

Peyrard (2019):agoodsummaryisintuitivelyrelatedtothreeaspects

Related Works• Forinformativeness• Linguisticallyspecificwords• Domainterminologies• Topicwords

• Forredundancy• Similarity-basedmethodstoannotateredundantutterances

• For relevance• Topicsegmentation

4

Problems• Reliedonhumanannotations.

• labor-consuming

• Obtainedviaopen-domaintoolkits

• Dialogueagnostic

• notsuitablefordialogues

5

Pre-trained Language Models

6

DialoGPT Annotator

7

Overview• KeywordsExtraction:Extractsunpredictablewordsaskeywords.• TopicSegmentation:Insertsatopicsegmentationpointbeforeoneutteranceifitisunpredictable.• RedundancyDetection:Detectsutterancesthatareuselessforcontextrepresentationasredundant.

8

Keywords Extraction: DialoGPTKE• Motivation:ifonewordinthegoldenresponseisdifficulttobeinferredfromDialoGPT,weassumethatitcontainshighinformationandcanbeviewedasakeyword.• Extractsunpredictablewordsaskeywords.

9

Context: yoo guys. EOS1Response: hey wassup. EOS2Context: hey wassup. EOS2Response: Remmber the meeting EOS3Context: Remmber the meeting EOS3Response: I almost forget it. EOS4Context: I almost forget it. EOS4Response: fine EOS5Context: fine EOS5Response: Where? EOS6Context: Where? EOS6Response: at Barbara's place. EOS7

Tom: yoo guys. EOS1John: hey wassup. EOS2Tom: Remmber the meeting EOS3John: I almost forget it. EOS4Tom: fine EOS5John: Where? EOS6Tom: at Barbara's place. EOS7

Context-response Pairs

Original Dialogue

DialoGPT

hey

Remmber

wassup.

the meeting

EOS2

EOS3

Remmber the meeting

Golden:

loss31

Word-level and Utterance-level Loss

Prediction:Keywords Extraction

loss3loss32 loss33 loss34... Extracted

KeywordsAvg

loss31 loss32 loss33 loss34

...

loss71 loss72 loss73 loss34

Topic Segmentation: DialoGPTTS• Motivation:iftheresponseisdifficulttobepredictedgiventhecontextbasedonDialoGPT,weassumetheresponsemaybelongtoanothertopicandthereisatopicsegmentationbetweenthecontextandresponse.• Insertsatopicsegmentationpointbeforeoneutteranceifitisunpredictable.

10

Context: yoo guys. EOS1Response: hey wassup. EOS2Context: hey wassup. EOS2Response: Remmber the meeting EOS3Context: Remmber the meeting EOS3Response: I almost forget it. EOS4Context: I almost forget it. EOS4Response: fine EOS5Context: fine EOS5Response: Where? EOS6Context: Where? EOS6Response: at Barbara's place. EOS7

Tom: yoo guys. EOS1John: hey wassup. EOS2Tom: Remmber the meeting EOS3John: I almost forget it. EOS4Tom: fine EOS5John: Where? EOS6Tom: at Barbara's place. EOS7

Context-response Pairs

Original Dialogue

DialoGPT

hey

Remmber

wassup.

the meeting

EOS2

EOS3

Remmber the meeting

Golden:

loss31

Word-level and Utterance-level Loss

Prediction:

Topic Segmentation

loss3

SegmentationPoint

loss32 loss33 loss34Avg

loss2 loss3 loss4 loss5 loss6 loss7

SegmentationPoint

Redundancy Detection: DialoGPTRD• Motivation:If oneutterancebringsbringslittleinformationandhassmalleffectsonpredictingtheresponse,thisutterancebecomesaredundantutterance.• Detectsutterancesthatareuselessforcontextrepresentationasredundant.

11

Tom: yoo guys. EOS1John: hey wassup. EOS2Tom: Remmber the meeting EOS3John: I almost forget it. EOS4Tom: fine EOS5John: Where? EOS6Tom: at Barbara's place. EOS7

Dialogue Sequence

DialoGPT

yoo guys. EOS1 hey wassup. EOS2Remmber the meeting EOS3 I almostforget it. EOS4 fine EOS5 Where? EOS6 at Barbara's place. EOS7

Original Dialogue

yoo guys. EOS1... at Barbara's place. EOS7

...Dialogue Context

Representation

𝒉𝑬𝑶𝑺𝟏 𝒉𝑬𝑶𝑺𝟐 𝒉𝑬𝑶𝑺𝟕

∅

0.711

0.998

0.991

SimilarityCalculation

∅

Step: 1

Step: 2

Step: 3

0.642

Step: 4

Step: 50.573

Step: 60.993

5 4

Step: 0

∅

5 4

5 4

5

Redundantutterances

Steps

2

ℎ!"#!ℎ!"#" ℎ!"## ℎ!"#$ ℎ!"#% ℎ!"#& ℎ!"#'

ℎ!"#!ℎ!"#" ℎ!"## ℎ!"#$ ℎ!"#% ℎ!"#& ℎ!"#'

ℎ!"#!ℎ!"#" ℎ!"## ℎ!"#$ ℎ!"#% ℎ!"#& ℎ!"#'

ℎ!"#!ℎ!"#" ℎ!"## ℎ!"#$ ℎ!"#% ℎ!"#& ℎ!"#'

ℎ!"#!ℎ!"#" ℎ!"## ℎ!"#$ ℎ!"#% ℎ!"#& ℎ!"#'

ℎ!"#!ℎ!"#" ℎ!"## ℎ!"#$ ℎ!"#% ℎ!"#& ℎ!"#'

ℎ!"#!ℎ!"#" ℎ!"## ℎ!"#$ ℎ!"#% ℎ!"#& ℎ!"#'

Annotation Tags

12

Summarizer

13

BARTPre-trained PGN

Nonpre-trained

Dataset and Metrics• Datasets• SAMSum• AMI

• Evaluation Metrics• ROUGE• BERTScore

14

Statistics for SAMSum and AMI datasets

Automatic Evaluation

15TestsetresultsontheSAMSum dataset BERTScore

TestsetresultsontheAMIdataset

Human Evaluation

16

modelcangetthebestscoreinconcisenessmodelcanperform

betterincoverage

Effect of DialoGPTKE

17

• Entitiesplayanimportantroleinthesummarygeneration.

• CombinedwithDialoGPT embeddings,KeyBERT cangetbetterresults.

Intrinsic Evaluation For Keywords

• Viewreferencesummarywordsasgoldenkeywords

• BothTextRank andEntitiesperformpoorlyinrecall

• Ourmethodcanextractmorediversekeywords.

Effect of DialoGPTRD

18

• Rule-basedmethod:annotatesutteranceswithoutnoun,verbandadjectiveasredundant.

• OurmethodshowsmoreadvantagesforlongandverbosemeetingtranscriptsintheAMI.

Effect of DialoGPTTS

19

• OurmethodcangetcomparableresultswiththestrongbaselineC99(w/DialoGPT emb).

Ablation Studies for Annotations

20

• Forbothdatasets,trainingsummarizersbasedon datasetswithtwoofthreeannotationscansurpasscorrespondingsummarizersthataretrainedbasedondatasetswithonetypeofannotation.

• SummarizersthataretrainedonDKE+TS stillgetimprovementsonbothdatasets.

Conclusion• WeinvestigatetouseDialoGPT asunsupervisedannotatorsfordialoguesummarization,includingkeywordsextraction,redundancydetectionandtopicsegmentation.

• Experimentalresultsshowthatourmethodconsistentlyobtainsimprovementsuponpre-traind summarizer(BART)andnonpre-trainedsummarizer(PGN)onbothdatasets.

• Combiningallthreeannotations,oursummarizercanachievenewstate-of-the-artperformanceontheSAMSum dataset.

21

Thanks!