A Dialogue Robot System to Improve Credibility
in Sightseeing Spot Recommendations
Naoki Yoshimaru1, Tomohiro Masuda2, Hyejin Hong2, Yusei Tanaka2, Motoharu Okuma2,
Nagihiro Matsumoto2, Kazuma Kusu1, Takamasa Iio2, and Kenji Hatano2
Abstract— Various studies have been conducted on human-
supporting robot systems. These systems have been put to
practical use over the years and are now seen in our daily
lives. In particular, robots communicating smoothly with people
are expected to play an active role in customer service and
guidance. In this case, it is essential to determine whether the
customer is satisfied with the dialog robot or not. However, it
is not easy to satisfy all of the customer’s requests due to the
diversity of the customer’s speech. In this study, we developed a
dialog mechanism that prevents dialog breakdowns and keeps
the customer satisfied by providing multiple scenarios for the
robot to take control of the dialog. We tested it in a travel
destination recommendation task at a travel agency.
I. INTRODUCTION
A dialogue robot competition is being held to test mul-
timodal dialogue techniques using humanoid robots[1]. In
that dialog robot competition, a humanoid robot acts as a
counter-sales person for a travel agency and recommends
travel destinations to users. Participants compete in terms
of user satisfaction with the robot’s recommendations and
the naturalness of the dialogue. In order to improve user
satisfaction, it is necessary to not only present information
on travel destinations but also to listen to user requests and
recommend destinations that meet those requests.
It is not easy to listen to user requests through dialogue,
respond to those requests, and reflect those requests in the
recommendations. In particular, when users are allowed to
speak freely, classical rule-based dialogue systems often
break down. This is because the content of user utterances
is diverse, and it is impossible to prepare rules for all
utterances. The breakdown of dialogue can be avoided by
processing the occurrence of utterances that do not exist
in the rules(exception handling). However, frequent occur-
rences of exceptions may reduce user satisfaction. These
problems also arise in example-based dialogue systems.
Another approach is to use a generation-based dialog system.
Generative dialogue systems can generate natural responses
using large-scale language models and prompts. However,
for the specific task of recommending destinations, they may
generate information that is not true (fake information). For
example, the system may output information about exhibits
or products that do not exist in the destination description.
Since such fake information may cause ethical and legal
problems, adopting this method with current technology is
1Graduate School of Culture and Information Science, Doshisha Uni-
versity, 1-3 Tatara-Miyakodani Kyotanabe, Kyoto 610-0394, Japan
2Faculty of Culture and Information Science,Doshisha University, 1-3
Tatara-Miyakodani Kyotanabe, Kyoto 610-0394, Japan
not easy. Therefore, this study adopts a rule-based dialogue
system where the designer has complete control over the
utterances, although it is not as versatile as a generation-
based dialogue system.
In a rule-based dialog system, the robot must take the
initiative in the dialog to reflect the user’s requests in the
recommendations. Specifically, the robot takes the initiative
in the dialog robot by repeatedly asking the user questions.
Here, the robot’s questions should be questions that can be
answered with Yes/No or choices (choice-type questions).
For example, ”Do you travel alone? Or do you travel with
your family or friends?.” These questions should be designed
so that the user can answer them. Such questions implicitly
limit how users respond, making it easier to predict their
answers. As a result, it can reduce the possibility of dialogue
breakdown while still allowing the user to speak regarding
the destination recommendation.
However, in recommending travel destinations, the user is
not likely to be fully satisfied if the robot takes the initiative
in the dialog and asks many questions. Methods in which the
robot takes the initiative in dialog have been applied to daily
conversations with the elderly [2], and dialog with visitors
at events [3]. According to those studies, the method can
elicit some degree of user satisfaction. However, the dialogue
in those tasks is closer to chit-chat and different from
the dialogue in recommending travel destinations. Being
bombarded with questions by the robot in a chat is, in a
sense, easier for the user, who has no purpose in interacting
with the robot. This is because the user does not have to
think about what to say to the robot. On the other hand, in
recommending a travel destination, the user has the explicit
goal of selecting a destination. Therefore, it is important that
the robot’s questions are meant for destination selection and
that the user’s answers are reflected in the final destination
recommendation.
In this study, therefore, a dialog system was developed
in which the robot takes the initiative in the dialog and, in
addition to the method of specifying the customer’s requests
with choice-type questions, a mechanism was introduced
to memorize the user’s speech and reflect the content of
the user’s speech in the recommendations. The objective
is to show through a dialog robot competition 2022 [4]
(DRC2022) what extent customers are satisfied with the sys-
tem and to what extent they are receptive to the destinations
recommended by the robot.
arXiv:2210.11223v1 [cs.RO] 20 Oct 2022