An Adaptive, Emotional, and Expressive Reminding System
Nadine Richard and Seiji Yamada
National Institute of Informatics
2-1-2 Hitotsubashi, Chiyoda-ku
Tokyo-to 101-8430, Japannadine@nii.ac.jp and seiji@nii.ac.jp

Abstract
We are currently developing an adaptive, emotional, andexpressive interface agent, which learns when and how
to notify users about self-assigned tasks and events. In
this paper, we describe the learning system and the user
feedback mechanism we have designed. Then, we discuss issues concerning the expression of emotions, inthe situation where the user should not be distracted byan adaptive tool and is not expected to create a strong
relationship with it.

Introduction
An interface agent is a mediator between an automated service and a human being. The interaction with such an agent
extends from a simple command line to a natural conversation with a human-like digital actor or a robot. As a particular case of interface agents, personal assistants help us
reducing the ever-growing load of information, events andvarious commitments we need to handle, for instance bylearning how to organize and keep track of relevant items.
When designing a context-aware, interactive learning system, two major issues are:• Selecting an appropriate set of input values, including information about the current context of both the user andthe application.
• Choosing a feedback mechanism, to let the user reward or
punish adaptive components after they respectively leadto correct or incorrect actions.
In the case of an expressive interface agent, an additionalquestion is whether the displayed emotions can influence theuser positively when interacting with the agent.
In this paper, we present our on-going work on an adaptive, emotional, and expressive assistant for reminding ofself-assigned tasks and events. TAMAC OACH is an interface
agent that adapts to the organizational skills and preferencesof a user by learning when and how to present notifications,instead of requiring the user to set explicit alarms. Figure 1
presents a typical view of the TAMAC OACH GUI.
On the one hand, the triggering of a reminder depends on:• The relative temporal distance to the event starting date or
to the task due date.

Figure 1: The main window of the TamaCoach GUI.
• Various attributes that help to classify user habits andpreferences, e.g. contact information, priority or categories.
• The current status of the user: availability, on-going activity, physical location, and mood.
On the other hand, the form of a reminder mainly depends on the user status and on the capabilities of the device on which TAMAC OACH is running. A reminder can bepresented in different but combinable forms: a pop-up dialogue box, an e-mail message, a mobile e-mail message, ora sound alarm. The necessary data about tasks and eventsare extracted from I C ALENDAR files, which are produced
by an external calendaring or todo-management application.
We gather information about the current context of the user
through our GUI, and information about the agent execution
context through the operating system of the host device.
As users may interact infrequently with their calendaringapplication, designing an appropriate feedback system forthe learning module is a delicate issue. TAMAC OACH learns
from both:• Explicit interaction, through the dedicated GUI. For now,user actions in TAMAC OACH are limited to responding toa notification.
• Implicit interaction, through the user’s favourite calendaring application. User actions on calendar data include
adding a task, modifying a deadline, postponing a phone
call, indicating the completion of a task, etc.
For the explicit interaction, we propose to simply present
a notification together with a restricted set of user replies(e.g. accept or ignore), in order to get a direct but lessintrusive feedback from the user about the usefulness of thereminding system.
In the context of TAMAC OACH, we are also investigating
the effectiveness of expressed emotions regarding two separate goals:• Representing the self-satisfaction level of the agent in anatural and non-intrusive way, i.e. giving feedback on the
self-evaluation of the agent usefulness for the user.
• Influencing the user’s behaviour by inducing emotional
responses, at least to incite him/her to interact with ourreminding system.
In order to situate the purpose of our reminding system,
we first present some related work about personal assistantsand expressive interface agents. We then describe the overall architecture and the learning system of TAMAC OACH,
especially the contextual input data and the simple mechanism that gets feedback from the user. Before concluding
and presenting future work, we discuss the usual role of displaying emotions in virtual agents, and clarify the specificity
of our approach.

Yet Another Personal Assistant
Robotic or software personal assistants can be adaptive
recommenders for music or movies, helpers for home
appliances, e-mail filters, meeting negociators, exercise
coachs, TV presentors, museum guides, shopping assistants,
etc. Categories of issues concerning personal assistants
include machine-learning, interaction modalities, contextawareness, emotional display, interruption strategies, andthe social impact of affective agents. Interface agents
have been extensively studied by researchers from various
disciplines: agent-based systems and interface design ofcourse, but also psychology and sociology (Middleton 2001;
Moldt & von Scheve 2001; Shiaffino & Amandi 2002). In
particular, S. Shiaffino and A. Amandi state, in an excellent
survey, the main issues for building a virtual secretary: theneed for personalization, as each user would like to interact
with a different kind of assistant, and the reaction of users
towards interruptions, errors and explicit requests for feedback (Shiaffino & Amandi 2003).

Personal Time Managers
The management of personal calendars and todo lists isdifficult, in both personal and professional contexts: it re-quires remembering on-going activities, and continuously
rearranging priorities. People tend to remember quite well
the main tasks and events they are involved in, but they haveto face a growing volume and variety of information andcommitments, as well as more and more sources of interruptions.
As pointed out in (Berry et al. 2006), human time management has an intensely personal nature. People are usually reluctant to delegate this specific task to others, andeven more to software. They also have different preferences and practices regarding how they schedule their time.
Moreover, people tend to use various media to keep trackof things they intend to do (from paper post-its to mobile emails), and often do not record all the tasks and events theyshould remember (Bellotti et al. 2004). Interruption strategies are an important issue, as the task performance of ahuman may dramatically decrease when disrupted (Cutrell,Czerwinski, & Horvitz 2001; Shiaffino & Amandi 2003; Czerwinski, Horvitz, & Wilhite 2004; Weber & Pollack 2005;
Horvitz 2007). Therefore, a good personal time manager
should keep track of various sources of information andevents through different time scales, and should be awareof the current context of its user in terms of activity, availability, location or even emotional state, in order to notify
him/her when appropriate.
Calendars and todo managers are used to collect, maintainand organize lists of self-assigned tasks and events, with different natures, durations, regularities and frequencies. Electronic calendars and todo managers are different but closely
related applications, often part of PIM (Personal Information
Management) software suites. Within such tools, users can
set alarms for the most important events, such as meetingsor deadlines.
Many desktop or PDA (Personal Digital Assistant) applications, like S UNBIRD or E VOLUTION, propose traditional
ways of organizing todo-lists and calendars, but do not take
into account the multiple sources of task-oriented information. To overcome this lack, V. Belloti et al. have developed
TASK V ISTA (Bellotti et al. 2004) and TASK M ASTER (Bellotti et al. 2003). TASK V ISTA is a light-weight task list manager, which reduces the cognitive overload of informationand events coming from different sources (e.g. e-mail, todo
manager and Web browsing). TASK M ASTER enables users
to keep track of threads of activity and discussions, manage
deadlines and reminders, and mark-up tasks directly within
a single e-mail application. However, those applications do
not automatically adjust to the specific organizational habitsof their users.
On the other hand, adaptive systems like PTIME (as partof the PE X A assistant) learn about user scheduling habits
and preferences, mostly in order to autonomously negotiate
meetings (Berry et al. 2005; 2006; Myers et al. 2006). Like
most of the investigated office- or healthcare-related personal assistants, PE X A is a cognitive agent that learns andreasons about tasks, user behaviour and its own behaviour,in order to justify its actions, answer questions and give advice. Interestingly, it also performs some scheduling tasks
on behalf of the user.
Finally, AUTOMINDER is an adaptive reminding system,

intended for cognitively impaired elders, who prefer to live
at home (Pollack et al. 2003). It learns about routine activities, and monitors their daily performance in order to issue reminders whenever an essential task is not executed ontime.

Expressive Assistants
It has been demonstrated that the representation of an embodied agent strongly influences the motivation and the performance of the user when interacting with the application(Dehn & van Mulken 2000; Bartneck 2002). As advocatedin (Moldt & von Scheve 2001), interface agents should beequipped with emotional components, as emotions are an
efficient mechanism for reducing the complexity of interpersonal interactions. Displaying emotions through facial
expressions and gestures for virtual agents has now been
widely explored (Bartneck 2002; Isbister & Doyle 2002).
However, most applications concern ECAs (Embodied Conversational Agents), with complex dialogue abilities thatsimulate human behaviours. In particular, relational agentsbuild and maintain long-term social-emotional relationships
with their users. For instance in (Bickmore & Mauer 2006),
the authors conducted experiments with various interfaces(text-only, static image and animated virtual agent) for relational agents on PDAs. Animations include facial displaysof emotion, head nods, eye gaze movements, and posture
shifts. The experiments show that users tend to create relationships more easily with animated agents. Such humanlike agents are mainly developed for e-commerce or marketing (negociation, selling), healthcare (phobia or autism therapy, anxiety or exercise advisor), education (personal tutor)
and entertainment (games, story-telling).
Nevertheless, the positive impact of embodied agents that
express emotions still needs to be proven. As claimedin (Dehn & van Mulken 2000), it also strongly depends
on the application and on the kind of agent and representation considered. For instance, in some stressful situations, users can feel more comfortable when supported
by an empathetic assistant (McQuiggan & Lester 2006;
Prendinger & Ishizuka 2005; Creed & Beale 2006). On theother hand, R. Rickenberg and B. Reeves have observed thatthe social presence of an anthropomorphic agent can reducetask performance of users, in particular when the assistantseems to monitor their work (Rickenberg & Reeves 2000).
The agent representation can also mislead the users, andcause them to overestimate what the agent can do: an animated humanoid face is expected to conduct a dialogue innatural language, which would not be the case if the agent
was represented as a dog.
For more information about emotion-based architectures for autonomous agents and human-machine interfaces, recent reviews can be found in (Sarmento 2004) and(Spinola de Freitas, Gudwin, & Queiroz 2005).

In a company, the coach is a psychological expert, who temporarily helps employees to improve their work habits. The
coach uses various psychological prises to help subjects infinding, by themselves, their ways for improvement.
Although widely investigated for tutoring or healthcare
advising (Rickenberg & Reeves 2000; Nabeth et al. 2005;
Creed & Beale 2006; Bickmore & Mauer 2006), the psychological aspects of motivating a user have yet barely pertained
to the specific domain of time management assistance.

TamaCoachOur adaptive reminding system, TAMAC OACH, learns when
to interrupt the user, depending on a categorization of tasks
and events, and on the current context (time, user status, hostdevice). Our goal is not to help users in maintaining a todolist, but to learn when and how to remind them about what
they have explicitly planned to do. However, such an application is a complement to more complex assistants likePE X A, TASK V ISTA or TASK M ASTER.
Furthermore, an animated, emotional agent would be
more engaging: reducing the anxiety over a long list ofthings to do, or inducing amusement or even guilt, should
lead the user to better interact with TAMAC OACH and withhis/her calendaring application. We believe that the basic
expressivity of a cartoon-like, virtual creature should be sufficient, while providing a less intrusive and less distractive
interface for gathering user feedback than conversational
human-like assistants.
As suggested by its name, the ultimate purpose of the
TAMAC OACH project is to investigate virtual coaching in
the case of personal time management. Our mid-term goalis however to experiment on its adaptiveness and expressiveness.

Learning About Our Organizational Habits
The XCS-based learning system of TAMAC OACH decides
when to present a reminder to its user, and in what form. In
order to trigger an appropriate reminder, it is necessary to extract relative temporal distances and additional values fromI C ALENDAR data and past experiences, and to incorporate
the context of both the user and the application. Figure 2
exposes an overview of our general architecture.

Virtual coachs
As a psychological process, coaching aims at pushing a person to achieve a particular task. A sport coach trains a team,but essentially supports its members to lead them to victory.

Figure 2: The overall architecture of TamaCoach.

Two Cascaded Learning Classifier Systems
A Learning Classifier System is a set of rules (classifiers)
representing actions to be triggered depending on perceived
situations. Each rule is a pair of condition-action elements,
associated with a fitness value, which indicates the estimated efficiency of the rule. The condition part may contain insignificant items (environmental features that can beignored), meaning that the rule can be general and match
various situations. The fitness values are updated by incremental learning, depending on the success or the failure of the chosen rule for the current situation. Classifiers are added when new or more specific situations are detected. Then a Genetic Algorithm selects the best rules in
the whole set, while maintaining the size of the rule population. The XCS model has proved to be an efficient,
evolutionary, rule-based learning mechanism (Wilson 1995;
Butz, Goldberg, & Lanzi 2003). Like other Learning Classifier Systems, XCS has been extensively used for datamining and to control animats, but not to design interface
agents.
TAMAC OACH learns about two distinct functions: whento trigger a reminder, and how to present this notification to
the user. As shown in figure 3, the learning module is composed of two XCS-based Classifier Systems, with different
purposes. The first Classifier System (CS1) categorizes thedata concerning a given calendar item. Its output is a priority
value, which indicates how urgently TAMAC OACH should
produce a reminder for the item. Then, this priority value
is used to create a situation vector for the second Classifier
System (CS2).

Data From Calendar Files
Most of the conditional attributes in CS1 correspond to fields
provided by the I C ALENDAR format. I C ALENDAR data are
extracted and transformed before being stored into a local
database. Some attribute values are also computed from pastexperiences stored in the database, e.g. the average delay inachieving a given category of task. Most of the values inthe database take part in the decision process; in this case,before being sent to the learning system, the values are discretized. Categorical information like priority, transparency,
user-defined categories, or involved contacts are directly extracted from the raw I C ALENDAR files. The rest of the data,like the summary or the attached documents, is stored only
to be presented to the user in reminders.
We call relative temporal distance the distance between
the current date, and the starting date of an event or the due
date of a task. Such a value is required to decide when to
trigger a reminder. Discrete, multi-granular relative temporal distances are computed from I C ALENDAR dates, durations and reccurrence rules. To be relevant for the learning
mechanism of our agent, the raw distance is approximatedand translated into a symbolic value expressing how closethe current date is to the deadline or starting date. With
such a decomposition, a calendar item is easily categorized
as happening soon or in a long time.
Keeping track of the granularity is necessary, in order toconsider relative symbolic values like very close or far inan appropriate time context: an event that starts in five minutes is obviously close to happen, but the due date of a taskthat is expected to take 8 weeks to be achieved and is only
5% completed can also be considered as close in a weeks
time scale if the current date is less than 9 weeks before thedeadline. For clarity and efficiency purposes, we chose a
set of significant thresholds in order to categorize both the
granularity (from very short-term to long-term) and the approximate value of a distance (from very close to very far,or late1 ), instead of proposing functions for computing thiscategorization. More details on the processing of temporal
distances can be found in (Richard & Yamada 2007).

Historical Attributes

Figure 3: Architecture of the XCS-based learning system.
Depending on the current context of both the user and thehost device, and on the priority given by the first set of classifiers, CS2 is in charge of deciding if triggering a reminder
now is appropriate. If so, CS2 chooses the kind(s) of reminder to be produced. Because the possible reminder forms
are compatible (e.g. TAMAC OACH can launch a pop-up window and send an e-mail for the same item), the output of CS2
is a set of actions to be performed. As CS2 needs CS1 output to process the given situation, CS1 and CS2 are said tobe cascaded.

For learning a generalized classification of calendar items,
we assumed that the most useful data are the user-defined
categories assigned to an event or a task. Therefore, in orderto learn about the user habits concerning a kind of activity,
we propose to use additional attributes related to the categories of past events and tasks: the average duration and theaverage delay observed for a given category, plus a flag indicating whether the user is generally early when achieving
this kind of task or attending this kind of event2 .
On the other hand, notifications can be repeated only if theuser explicitly asks to be reminded later. As a frequent repetition of the same reminder will probably annoy the user,
1
This additional distance value can be used for each granularity,
in order to express the severity of the delay since the starting dateor the due date occurred.
2
If this is the case, the category delay represents how long before the deadline this kind of task is usually achieved.

information about previous reminders enables the system tolearn when to present again the same notification content.
We thus also store the following historical values for each
item: the number of reminders already triggered, and thetemporal distance since the last reminder. The distance tothe previous reminder, as well as the average duration anddelay for a category, have the same value domain as the granularity of temporal distances.

User Context
The user status is processed by the second Classifier System.
It is the agregation of the following information:• busy state: available, busy, very busy, away, signed-off• mood: very good, good, average, bad, very bad

As described in the general introduction of this paper,
TAMAC OACH learns only from both direct and indirect interactions with its user, respectively through the dedicated
GUI and by the successive modifications of the calendar data
via an external application.

Reminders
A reminder can be presented under combinable forms, depending on the context. Presently, only a few forms areavailable (pop-up window, e-mail, mobile e-mail, or sound).
However, other kinds of notifications could be added after
the learning system has proven to be effective. Figure 4
shows an example of pop-up task reminder.

• activity: work, leisure, vacation, commuting, sick, conference, meeting, etc.
• location: office, transportation, home, business trip, etc.
The domains of the location and the activity attributes canbe defined and extended by the user, while the busy state
and the mood have a fixed set of values. Presently, the user
status is gathered directly through the GUI. Nevertheless, itwould be more convenient and less distractive to detect theuser activity load automatically, through monitoring (keyboard/mouse activity, estimated posture, biosensors, etc.).
From the number and the priority of current tasks, extracted from I C ALENDAR data, we also compute the current
task load of the user. This value completes the information
about the busy state, which might not be accurate or updated
enough.

Device Context
The execution context of TAMAC OACH is also handled byCS2. It is composed of the following attributes:• device : desktop, laptop, PDA, etc.
• has network? : does the device have an active network
connection?
• has sound? : can the device play a sound?
Such information is acquired from the operating system of
the hosting device. It is required to adapt the selected actions
to the execution environment: for instance, if the device has
no network connection, the reminding system cannot sendan e-mail.

Getting Feedback from the User
As stated by S. Shiaffino (Shiaffino & Amandi 2003), theprincipal source of learning for an interface agent is user
feedback. Such feedback can be either explicit (information
is given on purpose by the user to improve the agent behaviour) or implicit (the agent observes user actions). In
our case, because users may not interact very often with
their calendar and todo managers, the design of the feedback mechanism is particularly crucial. Moreover, our agent
has no means to detect the user attitude through facial expression recognition or physiological parameters, as seen in(Bartneck 2002; Prendinger & Ishizuka 2005).

Figure 4: A task reminder with four predefined replies.
Whatever form is selected by TAMAC OACH, the new reminder is also appended to the appropriate list of pending
events or pending tasks. If the lists are displayed in the
TAMAC OACH GUI, as in figure 5, selecting an item in a list
will make the corresponding non-modal pop-up reminder toappear.

Figure 5: The list of events within the main panel.
Together with a reminder, a set of possible replies is presented to the user. A notification will stay in the list until theuser directly answers back, by e-mail or through the GUI.
Any user reply causes the reminder to be deleted from theaccording list of pending tasks or events.

Direct User Feedback
Together with a reminder, a set of six possible replies is presented to the user. This light-weight, explicit feedback sys-tem enables TAMAC OACH to evaluate the quality of its actions, without disturbing busy users too much. As shown infigure 4, the main three possible replies are as follow:• Accept: the user thinks that the reminder is useful and will
act immediately, e.g. finish the task or attend the meeting.
• Later: the reminder has to be presented again later.
• Ignore: the user does not care about the reminder.
In the case of a later or ignore reply, the user can specify whether the reminder was respectively too early or toolate. This distinction is important to avoid taking a neutral
feedback as a punishment:• Later: the user may have found the reminder useful but
would like to be notified again anyway, e.g. if he/she cannot perform the task immediately. It does not necessarilymean that the reminder was issued too early.
• Ignore: the user informs the agent about his/her lack ofinterest in that particular task or event. It does not necessarily mean that the reminder arrived too late.
All the above replies concern the reminder itself: theygive direct feedback on the usefulness of TAMAC OACH actions. Nevertheless, we are dealing with I C ALENDAR files
that are modified by an external calendaring application.
When notified, the user may notice that he/she has not updated the calendar for the reminded task or event, e.g. thata report was completed, a meeting was postponed, or a dinner was cancelled. We thus added an update reply, whichindicates that the user will modify the calendar data in orderto reflect the actual situation. Again, this situation should
not be considered as a punishment by the learning system,
and could even been used to get further information about
the user habits. Note that TAMAC OACH could ideally detect such a situation and cancel the reminder if possible (e.g.
make the pop-up window disappear).
The items for which the user has replied accept, ignore or
too late are considered as acknowledged, and will not be processed by the learning system anymore. A later, too earlyor update reply might trigger a new reminder later.
The main advantage of having a limited number of predefined replies is that the user can quickly understand themeaning and the consequences of each action. The acquired
routine of answering to a reminder should reduce both theinterruption length and the cognitive overload when selecting an appropriate reply. A conversational or an adaptive interface would certainly be more disruptive and require more
attention from the user.

Remote and Delayed User Feedback
The user can interact with a running instance of TAMA C OACH via e-mails sent from a computer, a PDA or a mobile
phone. For now, this kind of remote interaction is possible
only when replying to an e-mail reminder. However, remotecontrol of the agent could be extended to other operations
available through the GUI.
The user may not reply immediately to a reminder for various reasons: for instance, he/she forgot to update the user
status before leaving the office, did not check his/her mobile

e-mails, or is too busy to reply by e-mail or through the GUI.
Delays in the user reply lead to delays in the feedback forthe triggering rules. However, a delayed reply should not
be considered as a negative feedback, as we cannot know
why the user did not react immediately. We thus just consider that, in case of a delay, the next reminders will not be
selected by an updated set of rules.

Simulating and Expressing Emotions
As stated in (Hassenzahl et al. 2000), the so-called fun factor is important to pull humans in using artefacts. Associating an expressive character to our reminding system might
motivate the user in honouring various self-assigned commitments, by being both engaging and as least distractive as
possible. We consider two compatible uses of basic emotional display:• Informing the user: the expressed emotions should reflect
the satisfaction level of the agent, in order to facilitate
the interaction with the user. We believe that displaying
emotions is a natural and efficient way to inform the user
about the estimated satisfaction level of the agent, i.e. theglobal evaluation of its usefulness.
• Influencing the user: the expressed emotions might increase the involvement of the user and thus incite him/her
in taking appropriate actions.
A basic reminding system does not require an elaborate
relational agent to make the user feel comfortable. Creatinga strong relationship with the agent could even be counterproductive, as it would distract the user. We thus believe thata non-cognitive agent, with limited learning and expressivity, should be sufficient for our purpose.

An Emotional System for TamaCoachOur emotional system is inspired from L. Sarmento’s architecture (Sarmento 2004). The agent emotional state is a setof emotional accumulators, associated with specific evaluation functions, appraisal thresholds and decay values. The
global mood, which is a long-lasting state, is calculated fromthe values of emotional variables, which represent shortlived phenomenons. As shown in figure 1, the mood is usedboth as a reward value for the learning system, and to display the emotional state of the agent through its graphicalrepresentation.
As suggested in (Spinola de Freitas, Gudwin, & Queiroz
2005), the choice of an appropriate set of emotions depends
on the application. Facial expressions should reflect theemotional state of the agent, in a simple but effective way,
and must be easily understood, so no distraction or overexpectation can arise from the user. We chose to focus
on a few basic emotions to be “felt” and expressed by theagent: joy, sadness, boredom, worry and surprise. Expressing happiness after several rewarding user actions should efficiently inform the user that the given responses improve
the learning system. On the opposite, sadness indicates thatthe learning system has received many successive negative
feedbacks, and thus evaluates itself as acting poorly. Boredom and worry both indicate that the user does not interact

enough with the application: TAMAC OACH gets bored when
there are few events and tasks to process, and starts to worry
when too many pending items are accumulating. Finally,
surprise may arise when the user reply to the notification
was unexpected.
The initialization of both the learning and the emotional
systems strongly depends on the personality of the user. A
user profile could be gathered through an initial questionnaire, in order to accelerate the learning process and reduce
the risk of inadequation of the agent personality. Moreover,the user should be able to give more precise feedback whenever the mood expressed by the agent seems inconsistent
with the actual satisfaction of the user. For instance, if theagent looks sad while the user actually finds the tool useful, the user could adjust the emotional system parameters
through a short questionnaire.

Why Expressing Emotions?
As previously discussed, the influence of relational, humanlike agents is rather controversial. In our case, the agent isjust a notification system, which learns to interrupt the user
only when relevant. We think that a conversational agent
would be unnecessary, and even distractive. Moreover, letting the user feel like being monitored and judged by ananthropomorphic agent about his/her organizational habits
might be counter-productive. Therefore, inspired by the famous TAMAGOCHI game, we chose to represent the agent
as a virtual creature, which simulates and demonstrates basic emotions.
A player does not expect his/her TAMAGOCHI to be smart,
but the expressed, basic needs and emotions are sufficient toencourage the human to feed, clean or play with the artificial creature. As with a TAMAGOCHI, we hope that inducing emotions like amusement or guilt will lead the user ininteracting with the reminding system and the calendar application. A limited social bond may even arise, if the user
comes to trust TAMAC OACH in effectively reminding items,
or enjoys interacting with it. We believe that this should naturally incite the user in taking appropriate actions to fulfil
self-assigned commitments, without being too distractive.

Conclusion
In this paper, we have presented our adaptive, emotional andexpressive reminding system. We have described our learning architecture, and defined the requirements in terms ofcontextual input data, to be extracted from raw data stored
in I C ALENDAR files, or obtained from the user and the hostdevice. We also have described how to get useful but lightweight feedback from the user, and how to extend the modular agent architecture with an emotional system. Finally, we
have discussed the role of expressed emotions within thisspecific case of human-agent interaction: as we ultimately
aim at developing a virtual coaching system applied to personal time management, we expect that the display of emotions on a simple, artificial creature would at least push theuser in interacting with its adaptive reminder and thus organize personal time more efficiently.
However, a coaching system should guide the user along
the consecutive steps required to achieve long-term tasks.

This is not yet possible with the scarce information provided
by I C ALENDAR files and the actual TAMAC OACH system:
we need to gather more information from the user abouttasks, events and contacts, take more historical data into account, and move towards project planning assistance.
We are developing a first prototype, incrementally testedon three different platforms: a desktop PC (GNU/Linux),a laptop (MS-Windows), and a PDA (Zaurus C-3000 under
GNU/Linux). In parallel, we are investigating how to simulate various user profiles for evaluating and tuning the learning system. Then, we will integrate the described emotional
system to display facial expressions. Afterwards, we willconduct experiments on human users, in order to validate
our hypothesis about the possible influence of an adaptive,
emotional time manager on different kinds of users. If theadaptive and expressive parts of our reminding system appear to be useful and accepted by the users, we will be able
to extend it with guidance abilities: TAMAC OACH would
then accompany its user through an introspection and selfimprovement process, and fulfil its role as a virtual coach forpersonal time management.

Acknowledgements
This research project is founded by the Japan Society for the
Promotion of Science (JSPS). We would like to thank theanonymous reviewers for their most valuable comments, aswell as Sébastien Duval (NII) for his constructive remarks.

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