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Robot understands events in your story- Chat-oriented dialogue system based on event understanding -Abstract
The proposed chat-oriented dialogue system can make users think the system understands the user’s utterances.
By understanding the user’s utterances as an event structure (a group of time, place, person, etc.), we achieve achat-oriented dialogue system that can sympathize and delve into topics during a chat. To understand a user’s
events from the user’s utterances, a system must understand various words/phrases in user utterances. To tacklethis problem, we focus on general words and phrases that are familiar in a chatting situation but difficult to extract
by conventional methods. Using this technology, systems can extract a user’s utterances by organizing theextracted information. In the future, we aim to foster a world where humans can converse with systems likehumans with mutual understanding by grounding the extracted information to the system and external knowledge.

System utterance generation based on event understanding
The system generates its next utterances corresponding to the user’s event, extracted from the user’sutterances as structured event information, by comparing the event with system knowledge.
Example of an extracted event structure

How was your summer vacation?

TimePlace
PersonActionFeeling

I went to Osaka!
Oh, did you go to USJ?
No, I went to Namba!
Oh, Namba! Did you eat takoyaki?

ate takoyaki

Example of similar events (system knowledge)

Yes, I searched on the internet
and went to a popular shop.

ユーザ
User

Summer vacation
Osaka/Namba

システム
SystemGood! Was it delicious?

Ability to empathize and delve into topics

TimePlace
PersonActionFeelingin vacation
Osaka/USJwith family
saw turtles
was cuteTimePlace
PersonAction
Feelingin September
Osaka/Nambawith friends
ate takoyaki
was delicious

This system was developed based on the dialogue system that won first prize in a live competition in Japan (2019).

Phrase detection in user utterance
To understand user’s events from his/her utterances, various types of words/phrases must be extracted.
By analyzing such words and phrases in chats, we achieve this extraction.
Example of location words/phrases in chats
ConventionalNE extraction

Proposedextraction

ItalyItaly

We went to the park near
Kyoto station.

Kyoto station

park near Kyoto
StationI often go to electricity shop.

(none)

electricity shop

User utterance（Red is location phrase）

I went to Italy.

70% chance that phrases that are not Named Entity (NE)appear in chats (in case of location words/phrases)

Extracted phrase
This weekend, I went to the park near Kyoto sta.
WhenWhere
Extracted general word

Ability to extract general words and phrases

References[1] H. Narimatsu, H. Sugiyama, M. Mizukami, “Detecting Location-Indicating Phrases in User Utterances for Chat-Oriented Dialogue Systems,”
in Proc. The Fourth Linguistic and Cognitive Approaches to Dialog Agents Workshop (LACATODA), 2018.
[2] H. Sugiyama, H. Narimatsu, M. Mizukami, T. Arimoto, “Empirical study on domain-specific conversational dialogue system based oncontext-aware utterance understanding and generation,” JSAI SIG-SLUD, 2018. (in Japanese)[3] M. Mizukami, H. Sugiyama, H. Narimatsu, “Event Data Collection for Recent Personal Questions,” in Proc. LACATODA, 2018.

Contact
Hiromi Narimatsu Email: cs-liaison-ml at hco.ntt.co.jp
Interaction Research Group, Innovative Communication Laboratory
Open House 2019
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