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<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta>
      <journal-title-group>
        <journal-title>The
TRAINS project: a case study in building a conver-
sational planning agent. Journal of Experimental &amp;
Theoretical Artificial Intelligence</journal-title>
      </journal-title-group>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="doi">10.1023/A:1015036910358</article-id>
      <title-group>
        <article-title>ADELE: Care and Companionship for Independent Aging</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Brendan Spillane</string-name>
          <email>brendan.spillane@adaptcentre.ie</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Emer Gilmartin</string-name>
          <email>gilmare@tcd.ie</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Christian Saam</string-name>
          <email>saamc@cs.tcd.ie</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Benjamin R. Cowan</string-name>
          <email>benjamin.cowan@ucd.ie</email>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Vincent Wade</string-name>
          <email>vwade@adaptcentre.ie</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>ADAPT Centre, Trinity College Dublin</institution>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>University College Dublin</institution>
        </aff>
      </contrib-group>
      <pub-date>
        <year>1995</year>
      </pub-date>
      <volume>7</volume>
      <issue>1</issue>
      <fpage>2</fpage>
      <lpage>3</lpage>
      <abstract>
        <p>Dialogue system technology offers interesting prospects for services to seniors living independently. A spoken or text dialog system can support services such as monitoring medication adherence, fall prevention and reporting, exercise and wellbeing coaching, entertainment, companionship and the maintenance of social networks. Such systems would amalgamate several different types of conversation or speech-exchange systems, from welldefined tasks to engaging talk. Knowledge of how these types of talk function is essential to system design. The ADELE project aims to build an agent, ADELE, which can provide a range of services to seniors. Below, we outline plans for the system and describe challenges we anticipate in implementing the system.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1 Introduction</title>
      <p>
        Spoken and text-based dialogue technology is the
focus of increasing interest in the domains of
geriatric care and coaching. These domains present
interesting challenges, as they rely not only on
the formulaic instrumental exchanges used in
taskbased systems, but also on an ability to
perform human-like casual and social talk.
Instrumental or task-based conversation is the medium
for practical activities such as service encounters
(shops, doctor’s appointments), information
transfer (lectures), or planning and execution of
business (meetings). A large proportion of daily talk
does not seem to contribute to a clear short-term
task, but builds and maintains social bonds, and
is described as ‘interactional’, social, or casual
conversation. Early dialogue system researchers
recognised the complexity of dealing with social
talk
        <xref ref-type="bibr" rid="ref1">(Allen et al., 2000)</xref>
        , and initial prototypes
concentrated on practical tasks such as travel
bookings or logistics
        <xref ref-type="bibr" rid="ref28">(Walker et al., 2001; Allen et al.,
1995)</xref>
        . Implementation of artificial task-based
dialogues is facilitated by a number of factors. In
these tasks, the lexical content of utterances drives
successful completion of the task, conversation
length is governed by task-completion, and
participants are aware of the goals of the
interaction. Such dialogues have been modelled as
finite state and later slot-based systems, first using
hand-written rules and later depending on
datadriven stochastic methods to decide the next
action. Task-based systems have proven invaluable
in many practical domains. However, the
creation of social companion application for
healthcare or senior use entails the ability to wrap
necessary tasks and recommendations in a matrix of
social conversation. Although the aim of such
agents is often described as conversational social
companions, the ability for dialog systems to chat
realistically lags their success in task based
dialogue. Below, we describe a typical use case for
our proposed system, ADELE. ADELE will be
capable of monitoring medication, providing
wellness advice and positive motivation, monitoring
exercise and daily habits, storing and prompting
general reminders, and engaging in
companionable, social dialogue. We then outline relevant
current approaches in dialogue systems and identify
key challenges for companionable social talk, and
highlight the challenges of supporting social talk
interaction. We outline early progress on ADELE,
and describe future work.
      </p>
    </sec>
    <sec id="sec-2">
      <title>ADELE Use Case</title>
      <p>The overall research goal of the ADELE project is
to explore the use of personalisation in improving
the efficacy of a digital companion that can
communicate through informal, yet informed social
dialogue, on a variety of topics of interest to a user
over a prolonged time scale. A key point for the
development of ADELE is that social spoken
dialogue requires knowledge of the user to inform
topic, style, and timing of conversation. This will
be achieved by adapting the system persona and
interaction based on the user’s interests and
profile to manage how and when the interactions
occur, their content, and the means by which they are
conveyed to the user to aid in comfortable, spoken
delivery. The following is an example use case
scenario between a future iteration of ADELE and
Emma, a 77 year old woman.</p>
      <p>ADELE: ”Emma, the next episode of that
medical TV show you like should be on soon.”
Emma: ”Oh great, I’ll check it out.”</p>
      <p>ADELE: ”In the meantime, you have time to do
your blood pressure daily check. I can then add
the results to your file.”</p>
      <p>Emma: ”Fine, let me just get the blood pressure
monitor.”</p>
      <p>ADELE: ”Your son Mark will also be here
tomorrow morning at 10 to collect you for your
doctors appointment.”</p>
      <p>Emma: ”Oh great, I’d forgotten about that. It’s
his birthday next Thursday - can you remind me of
that?”</p>
      <p>ADELE: ”Ok, would you like me to remind you
to give him a call on the day?”</p>
      <p>Emma: ”Thanks ADELE, that would be great!”
This interaction contains many elements which
demonstrate what an everyday conversation
entails, with topics flowing naturally. ADELE would
use the time between the reminder of the TV show
(a schedule reminder) and the actual start time to
recommend to Emma to check her blood pressure,
which must be done daily. This, like other user
recommendations and their responses, could be
marked as critical, resulting in regular reminders
and/or notification of a third party. ADELE could
also provide additional reminders such as a
doctor’s appointment. It could also reference events
such as Mark’s birthday, confirming with its
calendar and asking if Emma wanted a reminder set.
The use case scenario above raises a number of
research challenges, which will be explored during
the development of ADELE. There has been much
progress in dialog technology and there is a body
of work on the use of such systems in the elder
care domain. Below, we briefly overview some
existing systems.
3</p>
    </sec>
    <sec id="sec-3">
      <title>Current Elder Care Systems and</title>
    </sec>
    <sec id="sec-4">
      <title>Applications</title>
      <p>
        Academic work on companion applications and
agents for the elderly is well established, and
several commercial products have come to market.
The work of Bickmore’s Relational Agents Group,
which includes several applications of hybrid
social and task-based dialogue, is especially
pertinent to the ADELE project. Their Senior Exercise
Agent uses dialogue to encourage users to do more
exercise, with moderate success with health
literate adults
        <xref ref-type="bibr" rid="ref5">(Bickmore et al., 2013)</xref>
        . Their Virtual
Nurse system takes patients through the transition
from in-patient to discharge and aftercare through
a dialogue. Users liked the system more than
human doctors and nurses, citing the unrushed
quality of interaction with the agent, and the possibility
of re-checking every step without embarrassment.
The group have also created agents which explain
health documentation and provide counselling on
a range of topics. Their early work on REA, a
virtual estate agent which combined property
viewing tasks with social talk, provided foundation
research for hybrid task/social systems
        <xref ref-type="bibr" rid="ref28 ref3">(Bickmore
and Cassell, 2001)</xref>
        . The Serroga system is an
example of a non-speaking robot companion for
domestic health care assistance which assists senior
users in tasks from their day to day schedule and
health care
        <xref ref-type="bibr" rid="ref16">(Gross et al., 2015)</xref>
        . The system
emphasises social-emotional functions; in user trials
participants accepted the non-speaking robot as a
real social companion or relational agent. This
was largely due to the successful establishment of
co-presence. There is interesting recent work on
multimodal systems providing basic care for the
elderly and migrants (Wanner et al., 2016).
Commercial examples of social care robots include
ElliQ, Jibo, and GeriJoy1. The ADELE system
will be based on dialog system and recommender
system technology. Below, we briefly review
dialog system design most relevant to our purposes
and discuss challenges to the creation of casual
talk.
4
      </p>
    </sec>
    <sec id="sec-5">
      <title>Spoken Dialogue Systems</title>
      <p>
        Dialogue systems have predominantly focussed on
practical tasks. Classic dialogue systems are
usu1www.elliq.com, www.jibo.com, and www.gerijoy.com
ally based on a division into several modules that
handle the different problems of natural language
dialogue
        <xref ref-type="bibr" rid="ref17">(Jokinen and McTear, 2009)</xref>
        . The
Natural Language Understanding component converts
input into an internal representation that can be
reasoned on. The Dialogue Manager decides on
a next action and supplies the Natural Language
Generation with a specification of the next output
which it converts to natural language. Dialogue
management was initially based on handwritten
rules, but this approach is severely limited in
interactions other than simple question/answer
sequences. More recently, research has concentrated
on stochastic or machine learning methods, to
better handle the uncertainty, noise, and variability
inherent in spoken interaction. Stochastic dialogue
systems have relied on the availability of large
quantities of relevant data. While several dialogue
corpora exist, these are generally collections of
task-based dialogues, and not of casual talk
(Serban et al., 2015a). Traditional approaches require
this data to be labelled, adding significant cost to
research as corpus annotation is a time and labour
intensive undertaking. The ground truth provided
by labelled data furnishes a good training signal
to supervised learning for task-based interactions
which tend to be short and relatively predictable in
form and content. However, social talk can touch
on virtually any topic and exhaustive annotation
of corpora that capture realistic variation is
prohibitively expensive. Therefore, approaches where
labelling is not necessary are highly relevant.
Endto-End systems can be trained directly from user
input to system output without additional levels of
training data annotation. This advantage comes
at the price of requiring even greater amounts of
training data. Sequence-to-Sequence
        <xref ref-type="bibr" rid="ref23">(Sutskever
et al., 2014)</xref>
        models are a popular Neural
Network architecture which can achieve this goal.
These models have proven effective in a variety of
tasks. Early systems based on this approach
essentially translated from a user turn to a system turn
        <xref ref-type="bibr" rid="ref22 ref27 ref7">(Vinyals and Le, 2015)</xref>
        . Some current versions use
an additional level of hierarchy that allows the
system to take into account longer histories by
aggregating state information over previous turns
(Serban et al., 2015b).
5
      </p>
    </sec>
    <sec id="sec-6">
      <title>Challenges for Companionable Talk</title>
      <p>
        Personalised systems are concerned with
adapting and personalising services to individual users
based on a range of models
        <xref ref-type="bibr" rid="ref8">(Brusilovsky, 1998)</xref>
        .
Recent work on personalisation and dialogue
agents includes a customer service agent
        <xref ref-type="bibr" rid="ref26">(Verhagen et al., 2014)</xref>
        , a social robot tutor
        <xref ref-type="bibr" rid="ref15">(Gordona
et al., 2015)</xref>
        , and an eLearning agent (Peeters
et al., 2016). Dialogue management in digital
agents has long adopted personalisation strategies.
Recent contributions include Ultes et al, who
extended dialogue management to adapt to user
satisfaction
        <xref ref-type="bibr" rid="ref24">(Ultes et al., 2016)</xref>
        , Litman and Pan,
and San-Segundo et al. who developed
methods to adapt the overall dialogue strategy based
on the performance of the speech recognizer
        <xref ref-type="bibr" rid="ref2">(Litman and Pan, 2002; San-Segundo et al., 2005)</xref>
        ,
and Nothdurft et al. and Gnjatovic´ and Ro¨sner
have developed approaches to adaptive dialogue
        <xref ref-type="bibr" rid="ref13 ref4">(Nothdurft et al., 2012; Gnjatovic´ and Ro¨sner,
2008)</xref>
        . An early approach to combine a
personalised companion with adaptive dialogue was that
of Andre´ and Rist who developed personalised
information assistants for accessing information on
the web
        <xref ref-type="bibr" rid="ref2">(Andre´ and Rist, 2002)</xref>
        . More recently,
SARA was developed as a multifunctional
conversational agent capable of personalised
recommendations (Niculescu et al., 2014). To ensure a
social and personalised interaction, the type and
source of content that each user is recommended
should be based on their history and content that
they have explicitly expressed an interest in
during speech interaction. This content may include
news stories, conversational search terms or
individuals from social feeds
        <xref ref-type="bibr" rid="ref12">(Garcin et al., 2012)</xref>
        .
Each user also has preferred sources for such
content. These may also include preferred social
contacts such as close friends or family. A
personalised intelligent companion should be capable of
accessing and recommending content in a similar
fashion. This is a complex process and includes
topic extraction, weighting, mapping, longevity,
context etc. The nuances of people’s individual
interests and preferences are difficult to model and
require complex approaches to be accurately
captured, if they are to allow personalised services to
better meet the user’s needs. Efforts have been
made to include this ability in agents. Garcin et
al. developed a personalised news
recommendation system which demonstrated that collaborative
filtering provided the best results for
recommendations
        <xref ref-type="bibr" rid="ref12">(Garcin et al., 2012)</xref>
        . The content from
these favoured sources could be used to select
information to recommend when initiating or
taking part in social talk. The time, location and
context of delivery of interruptions are important
in social agent interaction. A conversational
social agent like ADELE needs to be able to
instigate conversation which would involve
interruption, but without excessively annoying or
disturbing the user. It is also important to ensure that each
interruption or conversation has a point and is
delivered in a concise manner. Likewise, it is
important that recommendations delivered within these
interruptions are not overly repeated or become
tiresome. The comparison by Bickmore et al. of
strategies for interrupting the user to instigate
exercise or take medication is highly relevant to this
research
        <xref ref-type="bibr" rid="ref4">(Bickmore et al., 2008)</xref>
        . There are
significant challenges around the time at which a
social agent should interrupt a user’s current task (to
initiate conversation) as well as how to interleave
with the user’s utterances to provide an effective
conversation. The urgency of the information or
request to be delivered by the agent should also
impact the agent’s interruption strategy, especially
in elderly care and social care contexts. Research
is also needed on personal adaptation of this
interruption pattern to suit individual tasks and user
preferences. There are also significant challenges
to be faced in the personalisation and
recommendation of content based on granularity, word
choice, comprehensibility etc. Much of the
relevant work is in personalised eLearning where the
delivery of content has received considerable
attention
        <xref ref-type="bibr" rid="ref10">(Daradoumis et al., 2013)</xref>
        . It is also
important to consider personality traits such as
friendliness, chattiness and professionalism of ADELE,
and the personality of the user. The importance
of personality development for personal and
virtual agents has been documented previously
        <xref ref-type="bibr" rid="ref11">(Doce
et al., 2010)</xref>
        . Research has also highlighted the
importance of matching a system’s personality with
that of its users
        <xref ref-type="bibr" rid="ref19">(Lee and Nass, 2003)</xref>
        . There are
also several contributions on modelling
personality traits, such as the framework of
McQuiggan et al. for modelling empathy (McQuiggan
et al., 2008). Further work is required to identify
and understand how these traits may be perceived
in social agent dialogue, the delivery of
personalised recommendations, and the extent to which
they need to be personalised to individuals.
Personalised recommendation and dialogue. based
on user personality has recently been investigated
        <xref ref-type="bibr" rid="ref23 ref25 ref7">(Braunhofer et al., 2015; Vail and Boyer, 2014)</xref>
        .
      </p>
      <p>
        ADELE’s user model needs to account for
physical and demographic attributes, usage preferences,
context and temporal requirements, etc. It will
also need to model additional attributes such as
personality, conversational preferences, and
critical care needs, such as medication requirements,
and long term care needs such as memory
monitoring. Many of these challenges and potential
solutions, have been detailed by De Carolis et al.
        <xref ref-type="bibr" rid="ref9">(Carolis et al., 2013)</xref>
        . Current chat-oriented
systems often exhibit a lack of variability in system
output. One approach to counter this is the use of
Reinforcement Learning to learn the production of
utterances that are more beneficial to the long-term
goal of the conversation
        <xref ref-type="bibr" rid="ref20">(Li et al., 2016)</xref>
        . A further
step is to drive this learning by adversarial training
which seeks to make system output
indistinguishable from human-generated conversation
        <xref ref-type="bibr" rid="ref21">(Li et al.,
2017)</xref>
        . Latent Variable models are another
technique that can sample from a learnt stochastic
variable to introduce randomness (Serban et al., 2017).
An extension is to make this process controllable
by making the distribution conditional on a
variable
        <xref ref-type="bibr" rid="ref22">(Sohn et al., 2015)</xref>
        . This can facilitate the
adjustment of a dimension that needs to be adapted
such as friendliness. To work over longer contexts
such as those found in casual interpersonal
conversation which may lapse and restart over the course
of hours or even days, memorization will need to
be addressed. Research into Memory Networks
has shown potential in the management of
intrasession context
        <xref ref-type="bibr" rid="ref6">(Bordes et al., 2016)</xref>
        , and may
prove applicable to the maintenance of longer
contexts in ADELE. One of the goals of the ADELE
system is to efficiently interleave different
‘subdialogues’ and sub-tasks - the system should be
able to break off from story-telling or casual chat
to perform a task such as medication checking and
then return to the previous activity. Both the chat
and task elements will vary between users
depending on their care model and circumstances. A
pertinent question is how to manage these different
sub-dialogues to promptly intervene to perform
subtasks? There has been some success with
reinforcement learning in this context, which is being
explored by the ADELE project (Yu et al., 2017).
6
      </p>
    </sec>
    <sec id="sec-7">
      <title>Current Focus</title>
      <p>
        Initially the ADELE project focused on
investigating the greeting and leavetaking phases of an
informal conversation. The project now aims to
investigate how to generate the body of a friendly
conversation (both interactive chat and longer
chunks). To this end the project is focussing on
topic shift and shading, the mechanisms which
underpin the development of such conversations
        <xref ref-type="bibr" rid="ref18">(Ries, 2001; Lambrecht, 1996)</xref>
        . Consequently, it
will be necessary for ADELE to be able to
identify, strategise, render, and initiate topic shift and
topic shading in a conversation. There are several
reasons for this. Firstly, it will allow ADELE to
change the course of a conversation. Secondly, it
will enable ADELE to more easily and more
naturally follow a conversation strategy, such as
recommending a television show. Thirdly, it will
enable ADELE to form more natural dialogue. The
ADELE project is currently identifying and
annotating examples of topic shift and topic shading in
Switchboard
        <xref ref-type="bibr" rid="ref14">(Godfrey et al., 1992)</xref>
        , a corpus of
2,400 two-sided telephone conversations. A
Wizard of Oz experiment based on a social care
scenario is being conducted to generate additional
social dialogues for training the Neural Network.
7
      </p>
    </sec>
    <sec id="sec-8">
      <title>Conclusion</title>
      <p>ADELE will be a virtual speech dialogue agent
capable of informal, yet informed social dialogue.
The importance of social dialogue to create social
bonds cannot be underestimated to support
independent living and companionship while
providing a means for task reminders to promote
beneficial self care. By treating the dialogue
management as a personalisation task, the dialogue system
can dynamically adapt to the users’ preferences to
enhance a more socially beneficial and
comfortable conversational interaction. This will require
an increased focus on personalisation strategies.</p>
    </sec>
    <sec id="sec-9">
      <title>Acknowledgements</title>
      <p>This research is supported by the Science
Foundation Ireland (Grant 13/RC/2106) and the ADAPT
Centre (www.adaptcentre.ie) at Trinity College,
Dublin.</p>
      <p>James F. Allen, Lenhart K. Schubert, George Ferguson,
Peter Heeman, Chung Hee Hwang, Tsuneaki Kato,</p>
      <p>Denmark, 2157–2169. https://www.aclweb.
org/anthology/D17-1230</p>
    </sec>
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