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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Dialogware - the \Software" for Conversational Agents: a Modular FrameNet-based Approach</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Fabio Massimo Zanzotto</string-name>
          <email>fabio.massimo.zanzotto@uniroma2.it</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Gioele Minardi</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Dario Onorati</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Gabriele Cocino</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Andrea Formichetti</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Dept. of Enterprise Engineering, University of Rome Tor Vergata</institution>
          ,
          <country country="IT">Italy</country>
        </aff>
      </contrib-group>
      <fpage>43</fpage>
      <lpage>50</lpage>
      <abstract>
        <p>Conversational agents are in every pocket where a smartphone is. It is the right time to foster a new generation of programmers to give a better personality to these conversational agents. In this paper we propose the dialogware as a novel form of software that should be produced by communication experts and artists: the dialogware programmers. We then introduce a modular FrameNet-based approach to dialogware programming along with a collaborative ecosystem for these new generation of programmers.</p>
      </abstract>
      <kwd-group>
        <kwd>Conversational Agents</kwd>
        <kwd>Chatbots</kwd>
        <kwd>FrameNet</kwd>
        <kwd>Modular Programming</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>Introduction</title>
      <p>Today, conversational agents are everywhere. Every pocket containing a
smartphone hides a conversational agent ready to answer questions or to help with
some everyday task. Conversational agents are not more con ned in the realm
of science ction. They are de nitely among us.</p>
      <p>
        There is a wide range of stable techniques for building these astonishing
conversational agents { a continuum from hand-crafting [
        <xref ref-type="bibr" rid="ref12 ref17 ref2 ref3 ref7">12, 17, 7, 2, 3</xref>
        ] to
automatic induction from existing interactions [
        <xref ref-type="bibr" rid="ref11 ref13 ref15 ref19">15, 13, 11, 19</xref>
        ]. Hand-crafted
converstional agents are considered relic of ancient past as automatically induced
models generally obtain impressive performances. But, sometimes automatically
induced conversational agents select extremely embarrassing answers and they
can be hardly decoded. In fact, inspecting thought vectors (as Geo Hinton calls
these vectors [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]) of neural networks dialog systems can be a useless activity. On
the contrary, hand-crafted conversational agents are clear enough to be easily
controlled. If the planner fails, programmers can debug and nd out what the
problem is.
      </p>
      <p>
        More important than the underlying technique, the key for the success of
these conversational agents is their actual knowledge for reacting to stimuli.
To have credible conversations, this knowledge should be produced or selected
by experts of communication, experts in writing poems, novels or stories, and,
nally, artists. In fact, these people are hired in conversational agent teams of
big players, for example, to de ne Cortana, Microsoft has hired Jonathan Foster
(a Hollywood lm and TV writer) along with other people with the previous
skills [
        <xref ref-type="bibr" rid="ref9">9</xref>
        ].
      </p>
      <p>Hence, this is the dawn of the \dialogware" { a new form of software to
program conversational machines. The \dialogware programmers" are the
programmers for this new form of software. But, they are not programmers in the
traditional sense and with the traditional software oriented mind. Hence, they
need more intuitive interfaces.</p>
      <p>
        In this paper, we propose the dialogware programming as a novel way of
programming and we present an associated community-based ecosystem oriented to
dialogware programmers. As any programming model, dialogware programming
is based on modularity and reuse. To foster the development of dialogware
modules, modules are organized using FrameNet [
        <xref ref-type="bibr" rid="ref4 ref6">6, 4</xref>
        ] and the dialogware
programming ecosystem is equipped with easy-to-use and intuitive interfaces, allowing
non-coders to easily contribute to the general dialogware library and to build
their own conversational agents. We leverage on coding experience like Scratch
[
        <xref ref-type="bibr" rid="ref14">14</xref>
        ], which are currently providing an option for non-programmers to code their
own mobile apps [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ] or program robotic environments [
        <xref ref-type="bibr" rid="ref16">16</xref>
        ].
ular approach, a basic hosting language and a way to produce dialog modules
on the basic hosting language.
2.1
      </p>
      <p>
        Building Conversational Agents by Combining Modules
The key point of our model is that conversational agents can be programmed
with reusable dialog blocks and these dialog blocks can be organized using
ontological languages and existing linguistic resources such as FrameNet [
        <xref ref-type="bibr" rid="ref4 ref6">6, 4</xref>
        ]. Hence,
building conversational agents can be divided in two clear parts: combining
dialog modules and programming speci c modules if needed.
      </p>
      <p>
        Having FrameNet [
        <xref ref-type="bibr" rid="ref4 ref6">6, 4</xref>
        ] and a set of ontological concepts, the activity of
programming a new conversational agent for a speci c task is the following. The
rst step is to select the prototypical situations, that is, the frames, involved in
the dialog. In a goal based dialog, frame elements of each frame are considered
as variables to be lled with a value through a conversation of the conversational
agent of the user. The second step is to describe how dialogs over these frames
interact in the general picture of the goal of the conversational agent. The last
step is to program the speci c dialogs for the speci c frames if these are not still
developed.
      </p>
      <p>For example, we want to build a conversational agent for a travel agency. The
goal of this agent is to gather the information needed to book the travel and the
related accommodation. In the rst step, we select the important frames which
are Travel and Temporary stay and we select additional dialogs such as the Initial
Greetings. The Travel frame has all the frame elements needed to book a trip {
source, goal, mode of transportation, traveler and time { and the Temporary stay
frame has all those to book an accommodation { guest, duration, time, place
and guest. In the second step, we combine the frame dialog blocks to obtain the
general dialog (see Fig. 1). The schema declares that the conversational agent
starts from the greetings. Once this state is accomplished, the next dialog block
is the Travel frame whose dialog aims to ll the free frame elements. The next
state is the Temporary stay frame and some of its frame elements are lled with
values of the previous state, for example, the goal of Travel lls the place of
Temporary stay. In the last step, we ll the dialog blocks which are not de ned.
2.2</p>
      <sec id="sec-1-1">
        <title>Basic Hosting Language</title>
        <p>To realize the strategy of building conversational agents by combining modules,
we need a basic conversational agent technology that keeps tracks of the state
of the conversation and has an explicit control of inner variables. These are the
only real prerequisites for our approach.</p>
        <p>
          Hence, we use the Arti cial Intelligence Markup Language (AIML) [
          <xref ref-type="bibr" rid="ref18">18</xref>
          ] as
host language. This language is based on a stimulus-response model where the
interactions of conversational agents are described by prototypical stimuli
associated to responses. Stimuli are written with a very simple pattern language
which allows a wild card called star that can match sequences of characters.
AIML has the de nition of the status of the dialog (topic), the possibility of
de ning paraphrases of prototypical stimuli with the so-called symbolic
reduction (srai), the possibility of introducing variability in the output with a random
choice between alternative responses and, nally, the possibility of managing
inner variables, that is, storing (set), retrieving (get) and checking (condition)
values.
        </p>
        <p>Although simple, AIML is enough versatile for hosting the rst version of
the dialogware programming paradigm.
2.3</p>
      </sec>
      <sec id="sec-1-2">
        <title>Programming Basic Modules</title>
        <p>Reusable goal-based dialog modules aims to ll a set of variables by asking
questions. These modules based on FrameNet and on ontological resources are
extremely interesting when building a goal-based conversational agent. As these
modules are one of the key point of our model, we present a way to program
these modules in a simple stimulus-response hosting language.</p>
        <p>In AIML, we realize these reusable goal-based dialog modules with three
main components: (1) a controlling backbone; (2) a set of interaction generators
to stimulate answers containing values for variables; and, (3) a set of answer
interpreters that capture values for variables.</p>
        <p>The dialog module conversation backbone aims to ll all the variables of a
given frame. Then, the backbone controls which variable has still to be lled
and initiates the dialog for stimulating answers to ll missing variables. This
backbone is then called when the state is entered and at the end of each answer
interpretation. Given a frame with the variables v1, v2, : : :, vn, the backbone is
a stimulus-response pair with the following aspect in a pseudo-language:
stimulus: ST ART P OIN T
response:
cases:
v1=;?: call: Request v1
v2=;?: call: Request v2
...
vn=;?: call: Request vn
def ault: call: F RAM EDON E
where ; is the empty value for a variable. This controlling backbone is called by
the stimulus ST ART P OIN T and calls Request vi for the rst variable vi which
is still empty. Request vi is the set of interaction generators that stimulates
answers for lling variable vi. When all the variables are lled with values, the
backbone calls F RAM EDON E. For example, for the frame Travel, variables
are Traveller, Source, Goal and so on.</p>
        <p>The set of interaction generators Request vi have the following form:
where \[Request vi interaction j]" is an actual utterance for asking to ll the
speci c variable vi. For example, for the variable Goal in the frame Travel, possible
interactions are \Where are you going?" or \What's your nal destination?".</p>
        <p>For each request Request vi, there is a set of answer interpreters that are in
charge of extracting variable llers from answers given by users. These answer
interpreters have the following form:</p>
        <p>[A possible answer
stimulus: to Request vi with a</p>
        <p>variable ller in *]
response:
set vi to : value that is lling *
call: ST ART P OIN T
Each answer interpreter captures a form of answer for a speci c request Request vi,
extracts the value for the variable with a wildcard , lls the variable vi and,
nally, call back the starting point of the dialog module. For example, a possible
answer to Request vi for the variable Goal is \I want to go to *". Then,
interactions like \I want to go to New York" will be matched and the value of will
be New York. The value of will be used to ll the variable Goal.
3</p>
      </sec>
    </sec>
    <sec id="sec-2">
      <title>Dialogware: the Programming Eco-system</title>
      <p>The Dialogware programming eco-system consists of two main parts: the Dialog
Diagram Editor and the Frame Editing. This section describes these two main
components and the overall implementation details of the ecosystem.
3.1</p>
      <sec id="sec-2-1">
        <title>Diagram Editor</title>
        <p>The Dialogware Diagram Editor is the core of the programming ecosystem. It
o ers a graphical interface for the de nition of creating the control diagram of a
goal-oriented conversational agent. The diagram editor is composed of two main
section: the sidebar and the actual canvas (see Figure 1). The sidebar contains
the palette of elements that can be added in the control diagram: frames and
static values. When a user clicks on the Add Frame button, the selected frame
is imported into the canvas. Then, the application prompts the user to specify
the status of the dialogue block in the overall diagram. The main canvas allows
to de ne the diagram by creating transitions among blocks (blue solid arrows)
and declaring how variables are lled from one frame to the other (green thin
arrows).
3.2</p>
      </sec>
      <sec id="sec-2-2">
        <title>Frame Editing</title>
        <p>The Frame Editing section is used to add interactions associated with the
elements of a frame, as well as to add the response pattern to them. The frame
editing allows to select the frame and to work on the interactions of the selected
frame. By selecting a frame and an element the Frame editor shows the list of all
questions associated with the selected frame element (see Figure 2 left panel).
Finally, by selecting the Answer's Patterns button, the frame editor shows all the
response patterns associated to the selected question. The Frame editor allows
to write both novel questions and novel possible answers from di erent users
(see Figure 2 right panel).
4</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>Conclusion and Future Work</title>
      <p>
        Conversational agents are a rapidly expanding market. We have presented an
approach to develop reusable dialog modules by introducing the dialogware as a
novel form of software. Splitting dialogware programming in blocks is
undoubtedly an e ective approach in terms of software development, as well as being an
e ective method to reduce the overall complexity of building knowledge for
conversational agents. As shown also for serious games [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ], FrameNet [
        <xref ref-type="bibr" rid="ref4 ref6">6, 4</xref>
        ] is a very
important source for organizing programming in general and the production of
dialogware modules in particular.
      </p>
      <p>The community of practitioners of conversational agents is rapidly increasing.
Our dialogware programming ecosystem wants to foster a revolution:
transforming artists, experts of communication and simple users of conversational agents
in developers of dialogware.</p>
      <p>
        In the future, by leveraging on techniques of semantic textual similarity [
        <xref ref-type="bibr" rid="ref1 ref20">1,
20</xref>
        ], we will improve our dialogware programming ecosystem by introducing
modules that expand interactions. This will speed up the manual and controlled
production of dialogware programs.
      </p>
    </sec>
  </body>
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