<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Archiving and Interchange DTD v1.0 20120330//EN" "JATS-archivearticle1.dtd">
<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Towards Enabling Cultural-Heritage Experts to Create Customizable Visit Experiences</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Carmelo Ardito</string-name>
          <email>carmelo.ardito@uniba.it</email>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Paolo Buono</string-name>
          <email>paolo.buono@uniba.it</email>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Maria Francesca</string-name>
          <email>maria.costabile@uniba.it</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Giuseppe Desolda</string-name>
          <email>giuseppe.desolda@uniba.it</email>
          <xref ref-type="aff" rid="aff4">4</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Rosa Lanzilotti</string-name>
          <email>rosa.lanzilotti@uniba.it</email>
          <xref ref-type="aff" rid="aff5">5</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Maristella Matera</string-name>
          <email>maristella.matera@polimi</email>
          <email>maristella.matera@polimi. it</email>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Antonio Piccinno</string-name>
          <email>antonio.piccinno@uniba.it</email>
          <xref ref-type="aff" rid="aff6">6</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Costabile</institution>
          ,
          <addr-line>Dipartimento di, Informatica</addr-line>
          ,
          <institution>Università, degli Studi di Bari</institution>
          ,
          <addr-line>Bari</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Dipartimento di Elettronica</institution>
          ,
          <addr-line>Informazione e, Bioingegneria, Politecnico, di Milano, Milano</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Dipartimento di, Informatica, Università, degli Studi di Bari</institution>
          ,
          <addr-line>Bari</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
        <aff id="aff3">
          <label>3</label>
          <institution>Dipartimento di, Informatica, Università, degli Studi di Bari</institution>
          ,
          <addr-line>Bari</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
        <aff id="aff4">
          <label>4</label>
          <institution>Dipartimento di, Informatica, Università, degli Studi di Bari</institution>
          ,
          <addr-line>Bari</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
        <aff id="aff5">
          <label>5</label>
          <institution>Dipartimento di, Informatica, Università, degli Studi di Bari</institution>
          ,
          <addr-line>Bari</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
        <aff id="aff6">
          <label>6</label>
          <institution>Dipartimento di, Informatica, Università, degli Studi di Bari</institution>
          ,
          <addr-line>Bari</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2018</year>
      </pub-date>
      <volume>2091</volume>
      <abstract>
        <p>In recent years, smart objects are increasingly pervading the environments we live in. Several studies highlight that Cultural Heritage (CH) is a very promising domain for IoT adoption, since this technology can favor the definition of smart visit experiences that engage visitors by allowing them to acquire CH content while interacting with the surrounding smart environment and the smart objects included in it. This paper presents new End-User Development approaches and the related abstractions that can support CH experts to create customizable visit experiences within museums and other cultural sites.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>CCS CONCEPTS</title>
      <p>• Software and its engineering → Application specific
development environments;
Internet of things; smart object behavior; tangible programming;
end-user development</p>
    </sec>
    <sec id="sec-2">
      <title>INTRODUCTION</title>
      <p>
        The recent Internet of Things (IoT) phenomenon and the
availability of a number of smart objects are pushing researchers to
exploit this technology in diferent domains [ 9]. Moreover, an
increasing number of end users, i.e., non-technical people not experts
in computer science, nor willing to be, want to use such a plethora
of smart devices for their daily activities, work, entertainment or
other purposes [
        <xref ref-type="bibr" rid="ref2 ref4 ref9">21, 23, 28</xref>
        ]. Several studies highlight that Cultural
Heritage (CH) is one of the most promising domains for IoT
adoption, since this technology can favour the definition of smart visit
experiences that engage visitors by allowing them to acquire CH
content while interacting with the surrounding environment and
the smart objects included in it [
        <xref ref-type="bibr" rid="ref10 ref12 ref14">8, 29, 31, 33</xref>
        ]. So far, even in the CH
domain, research on IoT has primarily focused on technical features
of smart objects [
        <xref ref-type="bibr" rid="ref11 ref7">13, 20, 26, 30</xref>
        ], while few approaches are trying to
facilitate the adoption of such a technology by end users in order
to foster the personalization of smart object behaviours. This lack
limits the social and practical benefits of IoT; it creates barriers in
all those usage scenarios where experts, e.g., museum curators and
guides in CH sites, would like to personalize the behavior of smart
objects but they usually do not have the required programming
skills.
      </p>
      <p>
        End-User Development (EUD) is a discipline that encompasses
methods, techniques, methodologies, situations, and socio-technical
environments that enable non-technical people to tailor software
systems to their needs and desires by modifying or even creating
software artefacts without requiring to write programs [
        <xref ref-type="bibr" rid="ref5">3, 15, 19,
24</xref>
        ]. Based on years of experience of the authors in EUD and the
works we recently carried out in the area of task-automation
systems [5, 18], this paper presents an ongoing research that aims to
provide non-technical users, as CH experts, with natural interaction
mechanisms to create smart visit experiences.
2
      </p>
    </sec>
    <sec id="sec-3">
      <title>BACKGROUND</title>
      <p>
        Diferent tools supporting non-technical users to configure smart
object behavior have been recently proposed. In particular, the
socalled Task-Automation (TA) tools [14] enable the combination of
social services, data sources and sensors, and have become popular
as they ofer very easy and intuitive paradigms to synchronize the
behavior of objects and applications [
        <xref ref-type="bibr" rid="ref6">11, 25</xref>
        ]. Through Web editors,
users can synchronize the behavior of smart objects by defining
Event-Condition-Action (ECA) rules [
        <xref ref-type="bibr" rid="ref8">27</xref>
        ], a paradigm largely used
for the specification of active systems (see for example [ 12, 16]),
which in the IoT domain can be fruitfully exploited to express how
and when some object behaviors have to be activated in reaction
to detected events. Many of such tools ofer visual, intuitive
interaction paradigms to graphically sketch ECA rules specifying the
interaction among the objects, for example by means of graphs
that represent how events and data parameters propagate among
the diferent objects to achieve their synchronization. This is not
a trivial task and it often requires data and system re-engineering
[10] together with test [
        <xref ref-type="bibr" rid="ref3">22</xref>
        ].
      </p>
      <p>
        Despite the popularity of such tools, very often their graphical
notations for rule specification do not match the mental model
of most users [
        <xref ref-type="bibr" rid="ref13">32</xref>
        ]. Another limiting factor is that the expressive
power of the ECA rules that can be specified is limited to very
simple synchronized behaviors. To overcome these limitations, we
designed a tool called EFESTO-5W for simplifying the creation of
ECA rules that combine smart object events/actions [18]. Some
of the EFESTO-5W visual mechanisms are inspired to the ones
available in the previous version of the platform used for data
source composition [
        <xref ref-type="bibr" rid="ref1">1, 6, 7, 17</xref>
        ].
      </p>
      <p>Some studies have shown that the EFESTO-5W composition
paradigm efectively guides users in establishing the behavior of
multiple smart objects [18]. However, we observed that in more
creative and rich contexts, like CH, smart objects cannot be simply
treated as "low-level" devices exposing events and actions, but they
bring with themselves their own semantics that refer to their role,
within the CH site, of mediators for content acquisition by visitors.
For example, a smart card depicting an Egyptian vase should not
be simply considered as a hexadecimal code that can be read by
an RFID reader; rather it represents a find dated back to a certain
époque, discovered in a particular place, having an ancient name.
This semantics could be exploited to simplify the definition of ECA
rules by stakeholders who are more interested in the semantics of
the objects (i.e., what content they can convey during the visit),
more than in the signals they can emit or they can receive as
input. In order to enrich smart objects with semantics, it should be
possible for domain experts to define the sensible attributes that are
representative of such a semantics.</p>
      <p>To reach this goal, we aim to extend our platform for ECA
rule definition by implementing intuitive and natural interaction
paradigms that allow non-technical users to define sensible
attributes on smart objects. In the following, we describe the
preliminary design of three novel paradigms.
3</p>
    </sec>
    <sec id="sec-4">
      <title>EXPLOITING CUSTOM ATTRIBUTES FOR</title>
    </sec>
    <sec id="sec-5">
      <title>DEFINING SMART EXPERIENCES</title>
      <p>To better explain what a smart visit experience is, we describe a
scenario where the main persona is Molly, a guide of the
archaeological park of Egnathia, which was an ancient Roman city in
Southern Italy. Molly first guides a group of visitors through the
ruins; she explains the history of the city and illustrates the places
in the park. Then, the visit continues in the park museum. Molly
engages visitors in playing a serious game in the "smart" rooms
of the museum. Here, display cases containing ancient objects are
instrumented with sensors able to detect NFC coins (resembling an
ancient Roman coin, used for identifying each visitor) each visitor
is provided with. During the game, Molly asks diferent questions
and, accordingly, sets the sensors of the display cases in diferent
modalities by means of an app installed on her smartphone. For
example, she sets the "Age = Roman" modality and asks visitors to
ifnd the display cases where Roman objects are shown. The visitors
move through the museum, identify the cases matching Molly’s
request and insert one of their own coins in the case coin slot. If they
are successful, the light inside cases turns green and the visitor’s
current score is increased. Then, Molly asks other questions and
sets the display cases in the corresponding modality, thus the game
continues focusing on the topic of the new modality.</p>
      <p>The synchronizations between cases and NFC coins are
established by the guide using our platform through the creation of ECA
rules, which define the synchronization between a single case and
a specific coin. Thus, Molly has to replicate this rule for coupling
all the other cases and coins.</p>
      <p>From the previous scenario, it is evident that the
personalization of a smart visit experience might not be limited to a trivial
synchronization of smart objects, but it might also require
creating digital narratives threads that professionals themselves need
to put in context with respect to the CH-site content. Driven by
these emerging requirements, we introduced the notion of custom
attributes [5], as a means to characterize smart objects not only by
native events and actions (as conceived in many IoT platforms) but
also by properties that the domain experts (i.e., the designers of
the smart experience) can define to assign semantics to the objects.
Such semantics empowers and simplifies the creation of ECA rules.
Visual mechanisms have been proposed to simplify the creation of
custom attributes and their association to smart objects [5].</p>
      <p>To understand some of the advantages of custom attributes and
how they can be visually defined in EFESTO-5W, let us go back to
the above scenario. Before creating ECA rules, Molly interacts with
a tool ofered by our platform, which allows her to assign attributes
to each case by manipulating widget interfaces, without the need
of writing code. In the example of Figure 1, she defines and assigns
the Age attribute, representing the age of the artifacts contained
by the cases, Points, representing the number of points the visitor
gains if the answer is correct, Blinking time, indicating for how
many seconds the case has to blink. From now on, the creation of
ECA rules can exploit this terminology (see for example Figure 2).
In Molly’s scenario, she does not need to define a multitude of very
similar rules for coupling every single case and coin, since they are
all encompassed by the single rule shown in Figure 2.</p>
      <p>Albeit the process illustrated above supports end users in
defining terms about a domain that can be useful when creating ECA
rules [5], we believe that there is room to improve the proposed
visual approach by means of more natural paradigms that facilitate
the attributes creation, stimulate the designers creativity and foster
the technology acceptance. Therefore, the ongoing research aims
to investigate intuitive and natural interaction paradigms that
allow to extend the native properties of a smart object (events and
actions) with custom attributes, in order to exploit them while
synchronizing smart objects.
4</p>
    </sec>
    <sec id="sec-6">
      <title>NOVEL EUD PARADIGMS FOR HANDLING</title>
    </sec>
    <sec id="sec-7">
      <title>SMART EXPERIENCES</title>
      <p>The starting point of this research was the identification of a set
of attribute types that the end users can exploit to describe the
semantic properties of smart objects. We found that types like text,
number, and geographic position can be used to define a wide
variety of significant attributes on smart objects. Starting from
these attributes, we designed three diferent composition paradigms
during a design workshop study involving 28 users arranged in
groups of 5/6 participants.</p>
      <p>The first paradigm is a tangible solution based on the use of real
objects representing the three types of attributes. Initially, each
group was asked to identify, for each type of attribute, at least one
object of the real world whose afordance refers to the attributed
meaning. For example, for the string attribute, objects like pens,
inkwell and sheet were proposed. Then, they were asked to propose
interaction mechanisms to combine physical attributes with smart
objects. In the resulting paradigm, each physical attribute can be
associated to a smart object by 1) putting close the smart objects
and the custom attributes they want to associate and 2) assigning
attribute name and value by using a post-it. For example, in Figure
3 in the left side of the desk, a smart card depicting a vase has 3
physical attributes around, each with a post-it indicating its name
and value. The design process implemented by this paradigm thus
occurs in the physical world. When the associations are established,
their digitalization/formalization is carried out by using a mobile
app that, by taking a picture of the desk, recognizes the smart
objects, the physical attributes, the associations among them and
the attribute names and values reported on the post-it, and creates
the custom attributes on the smart objects.</p>
      <p>The second paradigm is a pervasive solution based on the use of
the real world as a source of attributes. The surrounding
environment is conceived as a set of passive objects with their attributes.
Let us think, for example, to a museum in which there are paintings
and cases labeled with QR-codes that can be scanned with a
mobile phone to visualize additional information (e.g., style, painter,
history). These passive objects could be exploited to copy their
attributes and paste them into the smart objects. During our study,
each group was asked to figure out a solution to capture the
attributes of passive objects and to send them to the smart objects. In
the resulting idea, a smartphone is used to explore the surrounding
environment in an augmented reality fashion; here everything is
visualized in black and white, except the passive objects that expose
attributes. Indeed, they are augmented with colored pins, each one
associated with a type of attribute (e.g., a brown pin for a string
attribute). When a user approaches a passive object, its pins are
enriched by their names and values, according to a semantic-zoom
technique. Users can collect all the useful attributes, also edit their
names/values, and then they can scan a smart object to paste the
collected attributes.</p>
      <p>The third paradigm is a tactile solution based on the use of
a tabletop interactive display that was designed by some of the
authors of this paper exploiting their knowledge and expertise on
interactive displays [2]. The tabletop surface becomes a workspace
that facilitates the association between attributes and smart objects.
The attributes are represented as tangible objects, for example, the
ones used in the tangible paradigm. To assign an attribute to a
smart object, users putting on the surface the smart object (e.g. a
smart card); afterward, a proximity area appears around the smart
object (e.g., a rounded halo) meaning that physical attributes can
be placed inside it (see Figure 5). Each time a physical attribute is
put inside the area, a pop-up on the surface asks users to define the
attribute name and value.
5</p>
    </sec>
    <sec id="sec-8">
      <title>CONCLUSION</title>
      <p>This paper has presented an ongoing research on interaction paradigms
that can support domain experts in the creation of smart visit
experiences. Three diferent composition paradigms have been
identified, i.e. tangible, pervasive and tactile. As future work, we are
going to evaluate them by assessing their usability, their ability to
support the creative design of smart interactive experiences, and
their acceptance in real contexts, also comparing them with further
composition paradigm we implemented and 3D possibilities [4].</p>
    </sec>
    <sec id="sec-9">
      <title>ACKNOWLEDGMENTS</title>
      <p>The research described in this paper was supported by the Project
"Opera Lirica e Realtà Aumentata - opeRA" - Prog. n. F/050075/01/X32
- MISE - D.M. 1 Giugno 2016 "Horizon 2020 - PON 2014/2020".
[2] Carmelo Ardito, Paolo Buono, Maria Francesca Costabile, and Giuseppe Desolda.
2015. Interaction with Large Displays: A Survey. ACM Computing Surveys (CSUR)
47, 3, Article 46 (Feb. 2015), 38 pages. https://doi.org/10.1145/2682623
[3] Carmelo Ardito, Paolo Buono, Maria Francesca Costabile, Rosa Lanzilotti, and
Antonio Piccinno. 2012. End Users as Co-designers of Their Own Tools and
Products. Journal of Visual Languages &amp; Computing 23, 2 (2012), 78 – 90. https:
//doi.org/10.1016/j.jvlc.2011.11.005 Special issue dedicated to Prof. Piero Mussio.
[4] Carmelo Ardito, Paolo Buono, Maria Francesca Costabile, Rosa Lanzilotti, and
Adalberto L. Simeone. 2009. Comparing Low Cost Input Devices for Interacting
with 3D Virtual Environments. In Proceedings of the 2Nd Conference on Human
System Interactions (HSI’09). IEEE Press, Piscataway, NJ, USA, 289–294. http:
//dl.acm.org/citation.cfm?id=1689359.1689411
[5] Carmelo Ardito, Paolo Buono, Giuseppe Desolda, and Maristella Matera. 2018.</p>
      <p>From Smart Objects to Smart Experiences: An End-User Development Approach.
International Journal of Human-Computer Studies 114 (2018), 51 – 68. https://doi.
org/10.1016/j.ijhcs.2017.12.002 Advanced User Interfaces for Cultural Heritage.
[6] Carmelo Ardito, M. Francesca Costabile, Giuseppe Desolda, Rosa Lanzilotti,
Maristella Matera, and Matteo Picozzi. 2014. Visual Composition of Data
Sources by End Users. In Proceedings of the 2014 International Working Conference
on Advanced Visual Interfaces (AVI ’14). ACM, New York, NY, USA, 257–260.
https://doi.org/10.1145/2598153.2598201
[7] Carmelo Ardito, Maria Francesca Costabile, Giuseppe Desolda, Markus Latzina,
and Maristella Matera. 2015. Making Mashups Actionable Through Elastic
Design Principles. In End-User Development, Paloma Díaz, Volkmar Pipek, Carmelo
Ardito, Carlos Jensen, Ignacio Aedo, and Alexander Boden (Eds.). Springer
International Publishing, Cham, 236–241. https://doi.org/10.1007/978-3-319-18425-8_22
[8] Carmelo. Ardito, Maria Fransesca Costabile, and Rosa Lanzilotti. 2010. Gameplay
on a Multitouch Screen to Foster Learning About Historical Sites. In Proceedings
of the International Conference on Advanced Visual Interfaces (AVI ’10). ACM, New
York, NY, USA, 75–78. https://doi.org/10.1145/1842993.1843006
[9] Luigi Atzori, Antonio Iera, and Giacomo Morabito. 2010. The Internet of Things:
A Survey. Computer Networks 54, 15 (Oct. 2010), 2787–2805. https://doi.org/10.
1016/j.comnet.2010.05.010
[10] Alessandro Bianchi, Danilo Caivano, and Giuseppe Visaggio. 2000. Method and
Process for Iterative Reengineering of Data in a Legacy System. In Proceedings of
the Seventh Working Conference on Reverse Engineering (WCRE’00) (WCRE ’00).
IEEE Computer Society, Washington, DC, USA, 86–. http://dl.acm.org/citation.
cfm?id=832307.837101
[11] Federico Cabitza, Daniela Fogli, Rosa Lanzilotti, and Antonio Piccinno. 2017.
Rulebased Tools for the Configuration of Ambient Intelligence Systems: A
Comparative User Study. Multimedia Tools and Applications 76, 4 (Feb. 2017), 5221–5241.
https://doi.org/10.1007/s11042-016-3511-2
[12] Stefano Ceri, Florian Daniel, Maristella Matera, and Federico M. Facca. 2007.</p>
      <p>Model-driven Development of Context-aware Web Applications. ACM
Transactions on Internet Technology (TOIT) 7, 1, Article 2 (Feb. 2007). https://doi.org/10.
1145/1189740.1189742
[13] Angelo Chianese and Francesco Piccialli. 2014. Designing a Smart Museum:
When Cultural Heritage Joins IoT. In Proceedings of the 2014 Eighth International
Conference on Next Generation Mobile Apps, Services and Technologies (NGMAST
’14). IEEE Computer Society, Washington, DC, USA, 300–306. https://doi.org/10.
1109/NGMAST.2014.21
[14] Miguel Coronado and Carlos A. Iglesias. 2016. Task Automation Services:
Automation for the Masses. IEEE Internet Computing 20, 1 (Jan. 2016), 52–58.
https://doi.org/10.1109/MIC.2015.73
[15] Maria Francesca Costabile, Daniela Fogli, Piero Mussio, and Antonio Piccinno.
2007. Visual Interactive Systems for End-User Development: A Model-Based
Design Methodology. IEEE Transactions on Systems, Man, and Cybernetics - Part
A: Systems and Humans 37, 6 (Nov 2007), 1029–1046. https://doi.org/10.1109/
TSMCA.2007.904776
[16] Florian Daniel, Maristella Matera, and Giuseppe Pozzi. 2008. Managing Runtime
Adaptivity Through Active Rules: The Bellerofonte Framework. Journal of Web
Engineering 7, 3 (Sept. 2008), 179–199. http://dl.acm.org/citation.cfm?id=2011271.
2011273
[17] Giuseppe Desolda, Carmelo Ardito, and Maristella Matera. 2016. EFESTO: A
Platform for the End-User Development of Interactive Workspaces for Data
Exploration. In Rapid Mashup Development Tools, Florian Daniel and Cesare
Pautasso (Eds.). Springer International Publishing, Cham, 63–81. https://doi.org/
10.1007/978-3-319-28727-0_5
[18] Giuseppe Desolda, Carmelo Ardito, and Maristella Matera. 2017. Empowering End
Users to Customize Their Smart Environments: Model, Composition Paradigms,
and Domain-Specific Tools. ACM Transactions on Computer-Human Interaction
(TOCHI) 24, 2, Article 12 (April 2017), 52 pages. https://doi.org/10.1145/3057859
[19] Gerhard Fischer, Daniela Fogli, and Antonio Piccinno. 2017. Revisiting and
Broadening the Meta-Design Framework for End-User Development. Springer
International Publishing, Cham, 61–97. https://doi.org/10.1007/978-3-319-60291-2_4
[20] Piccialli Francesco and Chianese Angelo. 2017. A Location-based IoT
Platform Supporting the Cultural Heritage Domain. Concurrency and Computation:</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          [1]
          <string-name>
            <given-names>Carmelo</given-names>
            <surname>Ardito</surname>
          </string-name>
          , Paolo Bottoni, Maria Francesca Costabile, Giuseppe Desolda, Maristella Matera, Antonio Piccinno, and
          <string-name>
            <given-names>Matteo</given-names>
            <surname>Picozzi</surname>
          </string-name>
          .
          <year>2013</year>
          .
          <article-title>Enabling End Users to Create, Annotate and Share Personal Information Spaces</article-title>
          . In
          <string-name>
            <surname>End-User</surname>
            <given-names>Development</given-names>
          </string-name>
          , Yvonne Dittrich, Margaret Burnett, Anders Mørch, and David Redmiles (Eds.). Springer Berlin Heidelberg, Berlin, Heidelberg,
          <fpage>40</fpage>
          -
          <lpage>55</lpage>
          . https: //doi.org/10.1007/978-3-642
          <source>-38706-7_5 Practice and Experience</source>
          <volume>29</volume>
          ,
          <issue>11</issue>
          (
          <year>2017</year>
          ),
          <year>e4091</year>
          . https://doi.org/10.1002/cpe.4091 arXiv:https://onlinelibrary.wiley.com/doi/pdf/10.1002/cpe.4091
          <source>e4091 cpe.4091.</source>
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          [21]
          <string-name>
            <surname>Jayavardhana</surname>
            <given-names>Gubbi</given-names>
          </string-name>
          , Rajkumar Buyya, Slaven Marusic, and
          <string-name>
            <given-names>Marimuthu</given-names>
            <surname>Palaniswami</surname>
          </string-name>
          .
          <year>2013</year>
          .
          <article-title>Internet of Things (IoT): A Vision, Architectural Elements, and Future Directions</article-title>
          .
          <source>Future Generation Computer Systems</source>
          <volume>29</volume>
          ,
          <issue>7</issue>
          (
          <year>2013</year>
          ),
          <fpage>1645</fpage>
          -
          <lpage>1660</lpage>
          . https://doi.org/10.1016/j.future.
          <year>2013</year>
          .
          <volume>01</volume>
          .010
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          [22]
          <string-name>
            <surname>Beatriz PéRez Lamancha</surname>
            , Macario Polo, Danilo Caivano, Mario Piattini, and
            <given-names>Giuseppe</given-names>
          </string-name>
          <string-name>
            <surname>Visaggio</surname>
          </string-name>
          .
          <year>2013</year>
          .
          <source>Automated Generation of Test Oracles Using a Modeldriven Approach. Information and Software Technology</source>
          <volume>55</volume>
          ,
          <issue>2</issue>
          (Feb.
          <year>2013</year>
          ),
          <fpage>301</fpage>
          -
          <lpage>319</lpage>
          . https://doi.org/10.1016/j.infsof.
          <year>2012</year>
          .
          <volume>08</volume>
          .009
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          [23]
          <string-name>
            <given-names>Shancang</given-names>
            <surname>Li</surname>
          </string-name>
          ,
          <source>Li Da Xu, and Shanshan Zhao</source>
          .
          <year>2015</year>
          .
          <article-title>The Internet of Things: A Survey</article-title>
          .
          <source>Information Systems Frontiers</source>
          <volume>17</volume>
          ,
          <issue>2</issue>
          (April
          <year>2015</year>
          ),
          <fpage>243</fpage>
          -
          <lpage>259</lpage>
          . https: //doi.org/10.1007/s10796-014-9492-7
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          [24]
          <string-name>
            <surname>Henry</surname>
            <given-names>Lieberman</given-names>
          </string-name>
          , Fabio Paternò, Markus Klann, and
          <string-name>
            <given-names>Volker</given-names>
            <surname>Wulf</surname>
          </string-name>
          .
          <year>2006</year>
          .
          <article-title>End-User Development: An Emerging Paradigm</article-title>
          . Springer Netherlands, Dordrecht, 1-
          <fpage>8</fpage>
          . https://doi.org/10.1007/1-4020-5386-X_
          <fpage>1</fpage>
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          [25]
          <string-name>
            <given-names>Gabriella</given-names>
            <surname>Lucci</surname>
          </string-name>
          and
          <string-name>
            <given-names>Fabio</given-names>
            <surname>Paternò</surname>
          </string-name>
          .
          <year>2015</year>
          .
          <article-title>Analysing How Users Prefer to Model Contextual Event-Action Behaviours in Their Smartphones</article-title>
          . In
          <string-name>
            <surname>End-User</surname>
            <given-names>Development</given-names>
          </string-name>
          , Paloma Díaz, Volkmar Pipek, Carmelo Ardito, Carlos Jensen, Ignacio Aedo, and Alexander Boden (Eds.). Springer International Publishing, Cham,
          <fpage>186</fpage>
          -
          <lpage>191</lpage>
          . https://doi.org/10.1007/978-3-
          <fpage>319</fpage>
          -18425-8_
          <fpage>14</fpage>
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          [26]
          <string-name>
            <surname>Vincenzo</surname>
            <given-names>Mighali</given-names>
          </string-name>
          ,
          <source>Giuseppe Del Fiore</source>
          ,
          <string-name>
            <given-names>Luigi</given-names>
            <surname>Patrono</surname>
          </string-name>
          , Luca Mainetti, Stefano Alletto, Giuseppe Serra, and
          <string-name>
            <given-names>Rita</given-names>
            <surname>Cucchiara</surname>
          </string-name>
          .
          <year>2015</year>
          .
          <article-title>Innovative IoT-aware Services for a Smart Museum</article-title>
          .
          <source>In Proceedings of the 24th International Conference on World Wide Web (WWW '15 Companion)</source>
          . ACM, New York, NY, USA,
          <fpage>547</fpage>
          -
          <lpage>550</lpage>
          . https: //doi.org/10.1145/2740908.2744711
        </mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation>
          [27]
          <string-name>
            <surname>Jphn</surname>
            <given-names>F.</given-names>
          </string-name>
          <string-name>
            <surname>Pane</surname>
          </string-name>
          , Chotirat Ratanamahatana, and
          <string-name>
            <surname>Brad</surname>
            <given-names>A.</given-names>
          </string-name>
          <string-name>
            <surname>Myers</surname>
          </string-name>
          .
          <year>2001</year>
          .
          <article-title>Studying the Language and Structure in Non-programmers' Solutions to Programming Problems</article-title>
          .
          <source>International Journal of Human-Computer Studies 54</source>
          ,
          <issue>2</issue>
          (Feb.
          <year>2001</year>
          ),
          <fpage>237</fpage>
          -
          <lpage>264</lpage>
          . https://doi.org/10.1006/ijhc.
          <year>2000</year>
          .0410
        </mixed-citation>
      </ref>
      <ref id="ref9">
        <mixed-citation>
          [28]
          <string-name>
            <surname>Charith</surname>
            <given-names>Perera</given-names>
          </string-name>
          , Arkady Zaslavsky,
          <string-name>
            <given-names>Peter</given-names>
            <surname>Christen</surname>
          </string-name>
          , and
          <string-name>
            <given-names>Dimitrios</given-names>
            <surname>Georgakopoulos</surname>
          </string-name>
          .
          <year>2014</year>
          .
          <article-title>Context Aware Computing for The Internet of Things: A Survey</article-title>
          .
          <source>IEEE Communications Surveys Tutorials</source>
          <volume>16</volume>
          ,
          <issue>1</issue>
          (First
          <year>2014</year>
          ),
          <fpage>414</fpage>
          -
          <lpage>454</lpage>
          . https://doi.org/10. 1109/SURV.
          <year>2013</year>
          .
          <volume>042313</volume>
          .00197
        </mixed-citation>
      </ref>
      <ref id="ref10">
        <mixed-citation>
          [29]
          <string-name>
            <surname>Daniela</surname>
            <given-names>Petrelli</given-names>
          </string-name>
          , Elena Not, Areti Damala, Dick van Dijk,
          <string-name>
            <given-names>and Monika</given-names>
            <surname>Lechner</surname>
          </string-name>
          .
          <year>2014</year>
          .
          <article-title>meSch - Material Encounters with Digital Cultural Heritage</article-title>
          . In Digital Heritage. Progress in Cultural Heritage: Documentation, Preservation, and
          <string-name>
            <surname>Protection</surname>
          </string-name>
          , Marinos Ioannides, Nadia Magnenat-Thalmann, Eleanor Fink, Roko Žarnić, AlexYianing Yen, and Ewald Quak (Eds.). Springer International Publishing, Cham,
          <fpage>536</fpage>
          -
          <lpage>545</lpage>
          . https://doi.org/10.1007/978-3-
          <fpage>319</fpage>
          -13695-0_
          <fpage>53</fpage>
        </mixed-citation>
      </ref>
      <ref id="ref11">
        <mixed-citation>
          [30]
          <string-name>
            <given-names>Francesco</given-names>
            <surname>Piccialli</surname>
          </string-name>
          and
          <string-name>
            <given-names>Angelo</given-names>
            <surname>Chianese</surname>
          </string-name>
          .
          <year>2017</year>
          .
          <article-title>The Internet of Things Supporting Context-Aware Computing: A Cultural Heritage Case Study</article-title>
          .
          <source>Mobile Networks and Applications</source>
          <volume>22</volume>
          ,
          <issue>2</issue>
          (April
          <year>2017</year>
          ),
          <fpage>332</fpage>
          -
          <lpage>343</lpage>
          . https://doi.org/10.1007/ s11036-017-0810-4
        </mixed-citation>
      </ref>
      <ref id="ref12">
        <mixed-citation>
          [31]
          <string-name>
            <surname>Martin</surname>
            <given-names>Risseeuw</given-names>
          </string-name>
          , Dario Cavada, Elena Not, Massimo Zancanaro, Mark Marshall, Daniela Petrelli, and
          <string-name>
            <given-names>Thomas</given-names>
            <surname>Kubitza</surname>
          </string-name>
          .
          <year>2016</year>
          .
          <article-title>An Authoring Environment for Smart Objects in Museums: The meSch Approach</article-title>
          .
          <source>In Proc. Workshop on Smart Ecosystems cReation by Visual dEsign (SERVE '16)</source>
          .
          <source>CEUR-WS</source>
          ,
          <fpage>25</fpage>
          -
          <lpage>30</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref13">
        <mixed-citation>
          [32]
          <string-name>
            <surname>Usman</surname>
            <given-names>Wajid</given-names>
          </string-name>
          , Abdallah Namoun, and
          <string-name>
            <given-names>Nikolay</given-names>
            <surname>Mehandjiev</surname>
          </string-name>
          .
          <year>2011</year>
          .
          <article-title>Alternative Representations for End User Composition of Service-based Systems</article-title>
          .
          <source>In Proceedings of the Third International Conference on End-user Development (IS-EUD'11)</source>
          . Springer-Verlag, Berlin, Heidelberg,
          <fpage>53</fpage>
          -
          <lpage>66</lpage>
          . http://dl.acm.org/citation.cfm?id=
          <volume>2022939</volume>
          .
          <fpage>2022948</fpage>
        </mixed-citation>
      </ref>
      <ref id="ref14">
        <mixed-citation>
          [33]
          <string-name>
            <surname>Massimo</surname>
            <given-names>Zancanaro</given-names>
          </string-name>
          , Elena Not, Daniela Petrelli, Mark Marshall, Taco van Dijk,
          <string-name>
            <surname>Martin</surname>
            <given-names>Risseeuw</given-names>
          </string-name>
          , Dick van Dijk,
          <string-name>
            <surname>Adriano Venturini</surname>
            , Dario Cavada, and
            <given-names>Thomas</given-names>
          </string-name>
          <string-name>
            <surname>Kubitza</surname>
          </string-name>
          .
          <year>2015</year>
          .
          <article-title>Recipes for Tangible and Embodied Visit Experiences</article-title>
          .
          <source>In MW2015: Museums and the Web</source>
          <year>2015</year>
          .
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>