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  <front>
    <journal-meta>
      <journal-title-group>
        <journal-title>Feb</journal-title>
      </journal-title-group>
    </journal-meta>
    <article-meta>
      <title-group>
        <article-title>"The wheel" - an innovative visual model for interacting with a social web of things</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>G. Biamino, P. Grillo, I. Lombardi, F.</string-name>
          <email>grillo,lombardi,vernerof}@di.unito.it</email>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>R. Simeoni, A. Marcengo, A. Rapp</string-name>
          <email>@telecomitalia.it, amon.rapp@guest.telecomitalia.it</email>
          <email>amon.rapp@guest.telecomitalia.it</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Telecom Italia R&amp;T</institution>
          ,
          <addr-line>Via Reiss Romoli 274 - 10148 Torino - Italy, {rossana.simeoni,alessandro.marcengo}</addr-line>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Vernero, Dip. di Informatica - Università di Torino</institution>
          ,
          <addr-line>Corso Svizzera 185 - 10149 Torino -Italy, {biamino</addr-line>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2011</year>
      </pub-date>
      <volume>13</volume>
      <issue>2011</issue>
      <abstract>
        <p>Thanks to the evolution of identification and empowering technologies, interconnected and intelligent things are becoming popular in many domains. Depending on the kind of service smart things can offer, the possibility to identify and exchange services with them arises the significant problem of how users should interact and communicate with things themselves. It is therefore important to provide a proper interaction model, in order to help users in establishing a correct dialogue with empowered objects of the real world. Nevertheless, very little attention has been dedicated to the conceptualization of a good human-smart object interaction model and of an innovative visualization technique for networks of smart connected objects. In this paper we therefore present The Wheel, an interaction concept developed for WantEat suit of applications, designed to support the visualization and the exploration of identifiable things of the real world and their connections with other things. We propose a paradigm that enables a personalized, social and serendipitous interaction with networked things, allowing a continuos transition between real and digital world.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;Mixed Social networks of people and things</kwd>
        <kwd>ludic interaction</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. INTRODUCTION</title>
      <p>
        Empowered things of every day life have become more and more
important thanks to the spreading of Ambient Intelligence and
Ubiquitous Computing. Such a scenario opens new challenges for the
creation of innovative forms of communication and interaction
between people and things of the real world. In the WantEat project
[
        <xref ref-type="bibr" rid="ref9">9</xref>
        ] we introduced the idea that interacting with a social web of
smart things is an interesting way of getting in touch with the
cultural heritage of a territory. We call “smart” things which are
embedded social intelligence, i.e., which are capable of:
(a) creating and managing links with one another and with the
users they interacted with, i.e. the ability to maintain a
"Social Web" of things and people;
(b) playing an active role in managing the links in the social
network by establishing friendship relations with people and
other things, based on their knowledge and on the users’
behavior.
(c) structuring, aggregating and synthesizing contents and
sharing knowledge about themselves and the world around them;
(d) personalizing their interaction with users.
      </p>
      <p>The idea is that smart things tell us about the world around them,
the place in which they exist and its history and traditions. This
world is made of relationships which involve people and other things
and which evolve over time, given the interaction of people with
things and other people. A peculiarity of WantEat is that rather than
having a social network of users that discuss and express opinions
on things, we propose a social network of people and things, where
the two categories intermingle.</p>
      <p>In such a scenario, a need for innovative forms of interaction
allowing people to interact with things, to be introduced to their social
networks and navigate these networks emerges. Users should be
able to have a sensory contact with things of the real world and, at
the same time, enhance their experience by accessing further
information which is only available in digital form, e.g., by interacting
with an avatar of the thing itself. Users should also be able to access
the world around the thing, which is a complex one made of social
relationships with other things and people and of knowledge and
information about them. Thus, things should act as gateways
between the physical and the digital realms, welcoming users to their
social network. User interaction with things and their world should
be as easy and natural and possible, giving users the impression of
a real experience, and allowing a smooth transition between real
and digital. Moreover, interaction should be personalized
according to individual user profiles and to the context of interaction
(position, time, etc.) in order to support and guide users in their
exploration of mixed people and thing social networks. At the same time,
curiosity-driven exploration should be stimulated, so that users can
enjoy an entertaining and serendipitous experience.</p>
      <p>In order to achieve these goals, we devised the “Wheel”, an
innovative interaction model which allows to get in touch with things
of the real world, communicate with them and visualize and
explore their social networks. We therefore exploited novel forms of
information visualization and interaction technologies to design an
innovative human-object-interaction model.</p>
      <p>The paper is organized as follows. Section 2 illustrates a use case.
Section 3 introduces both the concept development and the
physical design. Section 4 presents WantEat, the suite of applications
using the here proposed interaction paradigm. Section 5 presents
the results of the user interface evaluation. Section 6 concludes the
paper.</p>
    </sec>
    <sec id="sec-2">
      <title>2. USE CASE</title>
      <p>Our domain of application is gastronomy as a way of getting in
touch with the gastronomic traditions and cultural heritage of a
territory. Things to get in touch with include food products, market
stalls, restaurants, shops, recipes but also geographic places and
actors such as cooks, producers, shop owners, etc. Interacting with a
food product (e.g., a bottle of wine) is a way of getting in touch
with the cultural heritage behind that wine, made of stories and
traditions, and with its social network, made of grapes, producers,
shops but also people who talked about it, people who tasted and
liked it, recipes that are perfect to taste the wine with, other
products that are "friends" of the wine (e.g., a cheese traditionally served
with the wine). As an additional advantage, productive chains can
also be shortened, allowing users a more immediate contact with
food producers and their territory.</p>
      <p>A scenario: John at the market. John is a tourist at the farmer’s
market of Springville and he is interested in the local traditions and
gastronomy. When he gets close to a cheese market stall he notices
a goat cheese which looks tasty and decides to try it. The cheese
tastes delicious and John decides to learn more about it. Using
WantEat application for his smartphone, John detects and
identifies that goat cheese making it the focus of his exploration. Thus,
he learns some basic information about it, discovering that it is
prepared according to a very ancient recipe by less than ten cheese
producers, all living in Springville. John decides to tag and bookmark
this cheese, and then he starts exploring its social network. Things
the system thinks he might be interested in and people with a user
profile similar to his are presented at first. For example, John
discovers that this cheese goes well together with local rhododendron
honey and is served as part of many typical dishes at Springville
tavern. His attention is captured by the recipe of a goat cheese
salad and decides to learn more about it. By making it the focus
of his exploration, he discovers that it is prepared with another
local product, cranberry mustard. Focusing on cranberry mustard, he
discovers that it is sold in a small shop nearby and decides to go
and buy it. Learning that John needs cranberry mustard in order
to prepare a goat cheese salad, the shopkeeper suggests him to buy
a bottle of Tandalay, a local white wine, which, she assures, is a
perfect accompaniment for goat cheese. Once at home, John
prepares the salad and tastes it with Tandalay wine. John is amazed:
a perfect match! He therefore decides to access WantEat system
again and post a comment for the goat cheese, suggesting to try it
together with Tandalay wine. Since also other users had suggested
the same match, the goat cheese and Tandalay wine become aware
of each other and a new link is added between them. Now, Wanteat
users can discover Tandalay wine by exploring the goat cheese
social network, and viceversa.
communicating with things and ii) visualizing things and exploring
their social network. The second aspect represents the core of our
concept, while the first one allows users to identify, communicate
with and use objects of the real world as a gateway for a
serendipitous exploration of their networks.</p>
    </sec>
    <sec id="sec-3">
      <title>3.1 Requirements</title>
      <p>Our main goal is to provide an innovative visual interface for
visualizing and navigating mixed object and user networks.
In order to properly design a valuable interaction model we started
by identifying a few requirements to allow human-object
interaction, mixed people and thing networks exploration and learning.
Since we follow the user-centered design approach, our attention
first focuses on users experience and needs. According to our view
users must be able to i) interact with objects in mobility, here and
now, ii) use common devices, such as their mobile phones, for
object identification, iii) learn something about objects with an easy
interaction modality and iv) communicate with objects, performing
social actions such as tagging, rating or leaving a comment.
Moreover users need to be able to perform several tasks in a transparent
and playful way thus improving their learning by doing. According
to this aspect other important requirements have to do with the
educational aspects related to the application: v) interaction should be
playful and entertaining; vi) interaction should support
serendipity and discovery; vii) interaction should stimulate curiosity and
support learning. Finally, since we wanted to keep interaction as
natural as possible, we identified three technological requirements:
viii) direct contact with the real world must be guaranteed, ix) no
infrastructure for object identification is needed (e.g., no
embedded electronics or tags are used), x) environment infrastructuring
should be minimized, xi) natural contact and interactivity are
expected.</p>
    </sec>
    <sec id="sec-4">
      <title>3.2 Getting in touch and communicate</title>
      <p>In accordance with the previously listed requirements, we
developed the following ways of creating the contact between a user and
a thing (fig. 1(a)):</p>
      <p>Taking a picture. The user frames the label of a product with
the camera; the label is recognized and a contact between the
user and the thing is created (fig. 1(b)).</p>
      <p>Geopositioning. The user can start the navigation by getting
in touch with a place (e.g., Springville village in the scenario
above) and thus with the things related to the place, i.e., the
things around him.
"Surprise"/"Recommend". The user can get in touch with
a random thing or get a recommendation based on his/her
preferences, position and social network.</p>
      <p>Bookmarking. The user can create a list of "preferred" things
and start the navigation from one of them. In other words, the
user can have a list of friends including users and things and
can get in touch with one of these friends at any time.
Searching things.</p>
    </sec>
    <sec id="sec-5">
      <title>3. THE WHEEL: AN INTERACTION MODEL</title>
      <p>In the this section we describe how we developed the interaction
model according to the previously mentioned goals. We first
illustrate the requirement analysis. We then discuss in detail our design
concept which is made of two main aspects: i) getting in touch and
In future work we will also consider the possibility that a thing
calls the user. If the application is turned on and a user gets close
to a thing that the recommender considers relevant for him/her, the
system can suggest him/her to get in touch with the thing. Since this
kind of proactive behavior could lead to user distraction, a good
balance should be found between information awareness and the
need to avoid frequent interruptions.</p>
      <p>Moreover, direct actions over objects are allowed for leaving or
getting information about them as soon as they’ve been detected.
Actions available are: rate, tag, comment, add to favorites. Users
are able to directly dialogue with the object identified without
having to access the whole system. The user interface (see fig. 1(g))
proposes a simple solution that emphasizes the immediacy of
interaction itself. The object detected is kept in the background and the
functionalities are displayed as buttons over it. Thus, users have the
impression of acting directly upon objects, just by using their
device. The interaction is kept natural and the merge between virtual
and real is preserved.</p>
    </sec>
    <sec id="sec-6">
      <title>3.3 Interacting with the thing and its world:</title>
    </sec>
    <sec id="sec-7">
      <title>The Wheel</title>
      <p>Concept. As stated before, things should act as gateways for
accessing the cultural heritage of a territory. Thus, as soon as users
have established a contact with a thing, they can both interact with
it, and access its social network.</p>
      <p>We devised an interaction model which supports users in
exploring such a social network, maintaining a strong focus on the thing
which served as a starting point, and at the same time allowing
users to discover and interact with its contacts. From a conceptual
point of view, the thing the user has got in touch with represents
the center of the world the user is going to explore. If the user
expresses interest in learning more about this thing, it should be
able to tell the user about itself, providing both general knowledge
and information synthesized from the interaction with other people
(including tags, comments, votes). Moreover, the user should be
allowed to perform direct actions (see Section 3.2), if she/he wishes
to enrich this thing with her/his personal experience.</p>
      <p>
        The thing in focus has many different relationships with people and
other things in the gastronomy domain: this aspect is represented in
our model by visually surrounding it with the members of its social
network. These can be grouped in homogeneous subsets (for
example, things related to the territory should be distinguished from
things related to cooking) and assigned to different areas around the
the central thing, in order to ease user exploration and to provide
an effective overview of the available information. Moreover, users
should have the chance to investigate the relationships which link
the central thing and its contacts, discovering: i) more information
about the relationship itself (e.g., if two valleys are connected to
each other because certain products are produced in both of them,
users should know what these products are), 2) if other things exist
which are in the same relationship with the central thing.
Design. We developed a "wheel" model. In a wheel, the object
that occupies the center represents the current focus, while objects
arranged along its circumference clearly appear to be related to it.
Moreover, the wheel radiuses embody the relations among objects.
Much research has been devoted to radial menus dating back to
the seminal work of Shneiderman [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ], based on the idea that they
can significantly decrease selection times. In our model a simple
form of spatial categorization is provided by partitioning the area
surrounding the center in four sections corresponding to four broad
macro-categories, which can vary according to the type of thing in
focus. Each thing belongs to one of the four sectors. In the
example of fig. 1(c), the thing in focus is a food product; the first wheel
("Territorio" – "Territory") contains the friends related to the
territory, the production and supply chain of the thing in focus (e.g.,
producers, shops, production places, etc.). The sector "Persone"
(a)
      </p>
      <p>(b)
(c)</p>
      <p>(d)
(e)
(f)
(g)
("People") contains people that are friends of the thing in focus
(e.g., who bookmarked it); the sector "Prodotti" ("Products")
contains other food products that are friends of the thing in focus (e.g.,
a wine that goes well with a cheese); the sector "Cucina"
("Cuisine") contains entities related to cuisine, such as cooks,
restaurants, recipes.</p>
      <p>Each sector can be expanded by touching it as shown in fig. 1(e).
The items can be explored by rotating the wheel, as an old style
telephone dialing selector. One item at a time is highlighted and the
relation between it and the thing at the center is explained. Items
in a sector can be ordered in a personalized way, for example
according to user preferences. Notice, however, that items are not
further categorized, so that users have to run through a sector in
order to find something interesting: in this way, our model supports
curiosity-driven exploration (rather than goal-oriented search) and
promotes serendipity. The user can continue exploration by
changing the thing in focus. This can be done by simply dragging one
thing towards the small wheel in one of the corners (fig. 1(f)). At
this point the whole wheel is recomputed and displayed to the user.
Using the wheel allows the users to explore a territory via the social
network of the intelligent things they meet and to exchange
information with them, thus matching our project requirements. When
they are interested in an object, users simply have to touch it in
order to access the available information. If their interest in this
object is even stronger, and they want to make it the starting point
of their exploration, they just have to drag it to the center of the
interface. This object becomes the new focus and the
surrounding related objects are updated accordingly. In addition, notice that
users always interact with specific instances (although possibly at
different levels of abstraction, as in the case of “Barbaresco” and
“red wine”), as it normally happens in real life, rather than with
categories in some sort of taxonomy, as it usually happens in
GUIstyle menus, thus making interaction more “natural” and decreasing
their cognitive workload (see requirements).</p>
    </sec>
    <sec id="sec-8">
      <title>4. WANTEAT</title>
      <p>WantEat is a suite of applications we designed that exploits the
interaction model described in this paper. In particular WantEat
Mobile is an application for Apple iPhone while WantEat Backshop
is a web application specifically meant for food producers.</p>
    </sec>
    <sec id="sec-9">
      <title>4.1 Notes on system design</title>
      <p>WantEat has been designed as a partially distributed one where we
distinguish: (i) a “server side" which is in charge of the creation
and management of the network of objects and people and which
contains the logic for creating intelligent adaptive behavior; (ii) the
“client side”, available on mobile smartphones (currently we are
using Apple iPhone) and on the Web, which is in charge of
managing the interaction between people and objects and networks; (iii)
the infrastructure for interacting with objects.</p>
      <p>The server side is constituted by a number of agents. First of all,
the system exploits an ontology of the application domain,
defining all the concepts in the domain and the relations among them.
For example, it includes a taxonomy of enogastronomical products
(e.g., of different types of cheeses based on different properties like
the type of milk and the production techniques), linking them to
actors (such as producers or market stall owners) and to places in a
geographic ontology. Inferences on the ontology allow the system
(i) to associate inferred properties to objects; these pieces of
information can be told by the objects to interested users; (ii) to create
links between objects. In fact, one way to create a link between two
objects is deducing it from some property they share in the domain
ontology.</p>
      <p>A second important agent is the social network manager. It is in
charge of managing links in the mixed social networks of things
and people. Two ways of managing links are considered.</p>
      <p>Links inferred from the ontology, e.g., linking products and
places or linking products with similar properties.</p>
      <p>links deriving from the behavior of users.</p>
      <p>User can interact with things in different ways. On the one hand
they can add tags, comments and ratings to a thing; on the one hand,
things tell stories to users, including information about them as
inferred from the ontology and syntheses of the tags and comments
provided by the users. This behavior is the basis from dynamically
creating (and removing) links between things and pople:
User-to-user links. Links between users are either created
explicitly by the users (e.g., links between a user and his/her
friends) or based on the analysis of users’ behavior. The
latter case includes, e.g., the links between users with similar
profiles or being in the same place at a given time or being
fond of a specific thing or a class of things.</p>
      <p>User-to-thing links are based on the user’s actions, i.e., a
user is linked to the things he/she bookmarked, commented,
tagged, rated positively or visited.</p>
      <p>Thing-to-thing links. These links are created by the system
based on the analysis of the users’ behavior and interaction
with things. An item X is linked to another item Y in case, for
example, X has been mentioned as a tag or in a comment on
Y, or in case X and Y appear frequently together in the
bookmarks of several users, or in case X and Y have been visited
frequently on the same occasion by several users. These links
are created by tracking and analyzing the actions performed
by the users and looking for significant correlations between
things. The same approach can be used to create further links
between users and things whenever the name of a user is
frequently associated by other users to a thing (or vice-versa).
Finally WantEat is an adaptive application which maintains an
explicit user model and exploits a recommender for selecting and
ranking information to be provided to a specific used based on
his/her model.</p>
      <p>One last word about infrastructuring. Minimizing all
infrastructures is an important goal of the project. The recognition of the
label of a thing is thus the main way to create a contact with the
user and this does not require intervention on the things.</p>
    </sec>
    <sec id="sec-10">
      <title>5. EVALUATION WITH USERS</title>
      <p>We adopted a user-centerd approach in the design of the interaction
model. Thus we performed user tests starting at the early stages of
the project. The first prototype of the wheel has been tested with 12
users who have been asked to perform a number of tasks, ranging
from thing recognition to navigation with the wheel. The prototype
was tested also to evaluate the following dimensions: easiness of
use, clarity, efficiency, effectiveness, usefulness. We also
investigated the level of learnability of the interface. All the users liked
the service; no major usability problem were pointed out; the users
evidenced some minor issues (e.g. the information about the
products should have a different distribution in order to increase the
homogeneity in the various sections of the application; the interaction
affordances, i.e. "back", "home", etc., should be more clear and
evident; etc.) that have been fixed in the final prototype which is
presented in this paper. Although the users found some interaction
problems at the first impact with the interface, the level of
learnability was very high. The final judgments expressed by the users
about the tested dimensions were positive. The users also provided
interesting comments about the advantages of using the application
while visiting an area or while visiting a market for discovering
products. Finally, the users suggest to improve the service adding
information about the prices of the products and the localization on
a map of the places in witch the products are produced or sold.
In order to further evaluate our concept we exploited WantEat
applications. In September 2010 we populated Wanteat with
information about the "Provincia di Torino" (Turin region) and its
enogastronomy. A test of the system has been performed afterwards with
two main goals: checking the stability and efficiency of the server
and validating the consistency of data entry. In October 2010 the
system was presented and tested by a wide public at Salone del
Gusto1. During 5 days of Salone del Gusto the application has
been used by several hundreds of casual users, who were very
enthusiastic about the services and opportunities offered by Wanteat.
The producers also had the opportunity to study the feedback from
the users. We collected 684 structured interviews from users who
evaluated the system and we will analyze the huge amount of data
from this test in the next months and we hope to have some first
results for the time of the workshop.</p>
    </sec>
    <sec id="sec-11">
      <title>6. RELATED WORK</title>
      <p>
        In this section we present some of the research literature and
applications related to our work. As regards mobile applications
connected to the notion of Internet of Things, an interesting project
is aPriori [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ]. It is an application that aims to connect people to
products exploiting the power of social recommendations and
object identification. With this application users can scan or search
for products using their mobile phone and they can read, post and
share comments about specific objects. This work does not offer a
real navigation among linked products, and according to our
framework, it stops at the second interaction modality (direct actions).
Interesting examples comes from tangible interfaces (TUIs) [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ].
Tangible computing is a central concept that refers to the
augmentation of the everyday world with computational power, in order to
allow entities to manifest natural behavior corresponding to their
environment and to users activities. While this gives people the
opportunity to interact directly through physical artifacts, in our
project we also want to investigate a new way of interaction with
smart things, which beyond their physical behavior, have to
naturally manifest enhanced behavior. An example of this paradigm is
Trackmate ([
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]) is an open-source tangible tracking system which
allows to recognize objects tagged with circular barcodes and to get
information on their position, rotation and color when placed on a
surface.
      </p>
      <p>
        Our work has similarities with SOFIA, a project that exploits
Semantic Web and ontologies in order to represent the objects’
knowledge for creating context aware smart objects [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ].
      </p>
      <p>
        As far as network visualization is concerned, some examples are
provided by visual search engines [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ], social network applications
such as Twitter [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ] and Digg [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ].
      </p>
    </sec>
    <sec id="sec-12">
      <title>7. CONCLUSIONS</title>
      <p>We introduced the idea of interacting with a social web of smart
things and we discussed an interaction paradigm for supporting this
idea. A prototype in the field of gastronomy has been implemented
and tested in a real world trial.</p>
      <p>In this paper, we focused on the novel interaction paradigm (wheel
model) we proposed for network visualization and exploration. Such
a model allows users to learn information about things they got in
touch with, discover related things and people in thier social
networks, learn more about the relationships linking network
memebers and enrich all these elements with their personal experience.
We believe that our interaction model can significantly improve the
way people experience the cultural heritage of their territory, by
1Salone del Gusto (www.salonedelgusto.it) is an event organized by
Slowfood in Torino every two years, with about 200000 visitors.
guaranteeing a faster, easier, and entertaining access to the world
and networks of things they find interesting.</p>
    </sec>
    <sec id="sec-13">
      <title>8. ACKNOWLEDGEMENTS</title>
      <p>The project has been partially supported by Regione Piemonte,
grant ICT Converging Technologies 2007. The authors are grateful
to Adriano Design (www.adrianodesign.it) for their support in the
graphic design of the interface.</p>
    </sec>
  </body>
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