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A Web-based platform for Scavenger Hunt Games
using the Internet of Things
Kiev Gama, Rafael Roballo, Daniel Maranhão, Vinicius Cardoso Garcia
Centro de Informática
Universidade Federal de Pernambuco – CIn-UFPE
Recife, Brazil
{kiev,rrw,dbm2,vcg}@cin.ufpe.br
Abstract— The concept of an “Internet of Things” (IoT)
initially referred to a network where objects would be
individually and instantly identified with Radio-Frequency
Identification (RFID). Such concept was later evolved to a wider
notion of heterogeneous objects using ubiquitous technologies to
interact among them and with the physical environment. Among
these technologies, Bluetooth, ZigBee, GPRS, NFC, QR code, can
be cited some of those that were labeled as IoT technologies.
Based on the possibility of linking ordinary objects from the
physical world to the Internet, this paper proposes and details a
platform called TagHunt, for creating and playing scavenger
hunt games. It allows smartphones to interact with ordinary
objects using IoT-based technologies such as NFC and QR Code,
stimulating the user/player to interact with the surrounding
environment looking for “clues” in the game. We performed an
experiment involving four different scavenger hunt game
scenarios created with the platform were we could evaluate
user/player engagement when playing such games.
Keywords—IoT, NFC, QRCode, Game platform
I. INTRODUCTION
The “Internet of Things” (IoT) is a term initially coined as
an analogy to a network where objects would be individually
and instantly identified with Radio-Frequency Identification
(RFID) [1]. The IoT vision is no longer limited to RFID, and
evolved to a universe of interconnected devices, objects and
things [20]. Nowadays it refers to a plethora of heterogeneous
objects using ubiquitous technologies to interact among them
and with the physical environment, partially fulfilling Mark
Weiser’s ubiquitous computing vision [19].
Besides RFID, many other wireless technologies lay the
foundations for the IoT, such as Bluetooth, ZigBee, GPRS,
NFC, among others [1][21]. We are particularly interest in
what is called Near Field Communication (NFC), an RFID-
based technology that has expanded in the market, with many
smartphones being shipped with that technology embedded on
them. New technologies unlock many possibilities; however,
NFC adoption is still unclear [8]. Currently, its usage scenarios
are limited by information exchange between smartphones [5]
and two other well established use cases: public transportation
payment [6] and electronic payment systems [7]. There are also
less widespread efforts employing NFC being used in other
contexts such as education, health, entertainment and culture,
as indicated in [18].
Following the IoT appeal that exists today, this project
wants to take advantage of the many types of IoT-related
technologies that are present in smartphones, including NFC.
We are motivated by the usage of object hyperlinking [18] in a
ludic way. In our context, physical objects from the physical
world, powered with IoT technology, would be used as
interactive elements in a digital gaming environment. The
interactive part of the game would run in the mobile device
while the intelligence concerning the game mechanics would
be part of gaming platform hosted in a cloud environment. This
concept would be capable of boosting NFC usage, as well as
other IoT technologies, in diverse scenarios such as games in
mixed-reality environments, urban environments, and
marketing campaigns, among other similar uses.
This paper proposes a novel scenario for the IoT, involving
objects from the physical world in a digital game. In such
games, participants will use smartphones to obtain data from
real world objects. The data will help users to be guided
through different steps in the game, in a traditional type of non-
digital game typically called Scavenger Hunt. In each step the
user will need to collect the information that will inform them
what (and where) would be the next step. In our context, the
information can be gathered from different types of interactive
objects (i.e. things) powered by different technologies (NFC
and QR code). A piece of collected information may lead the
game user to another source of information (e.g., a map, a Web
page) about the next step, or asking for additional information
(e.g., a quiz) in order to provide more information for the next
game step. The combination of NFC with Scavenger Hunt
games is relatively new, however existing approaches are
typically ad hoc. In this paper we propose a platform called
TagHunt, where any user could create a scavenger hunt game
along with its set of steps, each one mapped to a “clue” that can
be attached to physical objects identified through NFC or QR
code.
We performed an experiment that involved four different
Scavenger Hunt game scenarios created with the platform. The
goals of the experiment were twofold: (1) validating our
platform by using it to create scavenger games and (2) invite
actual users to test games created with our platform in order to
evaluate the user experience. We interrogated them concerning
their perception about the game. The first game scenario was
held in a controlled environment in an IT university (1500+
students), involving a population of 15 subjects. The other
scenarios were experienced within a famous technology
festival (4000+ attendants), in three distinct days involving 35,
28 and 38 subjects, respectively. After running the experiment
with users that were invited to play using their smartphones,
we were able to gather data about game usage as well as
interviewing a significant sample of the experiment’s
population. By analyzing the data, we could evaluate user
engagement when playing such games. Therefore, the
contributions of this paper are: (1) the notion of a platform for
the creation of scavenger hunt games employing object
hyperlinking; (2) the evaluation of user engagement in those
scenarios.
The remainder of this paper is organized as follows:
Section II provides more background on the main concepts
used in this paper and some motivations for our work. The
Section III introduces our Scavenger Hunt platform. Section IV
discusses experiment data. The Section V describes related
work; and finally, Section VI presents conclusions and future
work on the subject.
II. BACKGROUND AND MOTIVATION
The expansion of the concept behind the Internet of Things
(IoT) has opened new horizons in the development of
intelligent solutions to urban centers. Despite the popularity of
mobile devices, there is still resistance in the use of pervasive
devices, or simply the lack of information about their potential
[1]. These devices, based on pervasive (or ubiquitous)
computing aim to connect the world of information, services
available in the cloud, with users in the physical world, and the
whole environment around you. They are systems developed
with the aim of helping the citizen/user, considering the context
in which they are immersed, providing relevant information to
their day-to-day [2]. Providing intelligent services from
contextual information can be considered as one of the major
areas of business development, especially in the technology
field in the upcoming years, where the popularization of open
data and services (mainly government) will make life easier for
citizens/users in their day-to-day.
Nevertheless, the Internet of Things becomes a priority for
development and technological immersion in big cities. Some
countries even identify this concept as one of the technological
possibilities with the greatest potential impact on civil society
in the coming years [2]. Moreover, addressing the everyday
challenges with the help of technology leads us to new
fundamental concepts for the integration of all existing
ecosystem. Thus, we highlight the concept of Smart Cities. The
development of connected platforms, interconnecting users,
mobile devices, and contextual information from the
environment, making possible many interactions for the
development of new solutions.
As highlighted previously technological integration as a
mediator between the city and citizens can provide users with
significant interaction in urban centers, improving even the
lives of people. Schaffers et al. [16] list some points, where
there are some strategies, initiatives and key points, which
when implemented, address the feasibility of a Smart City For
example, the authors point out, among other things, that the
availability of infrastructure in the city, making it rich, and
with access to high-speed network environments, as well as
improving the interface of Smart Cities, provide sustainability
for the long process deadline. The availability of embedded
systems, sensors, real-time data are also contemplative for the
best development of intelligent environments factors. Finally,
the creation of new applications and games, the consumption of
data services, the introduction of collaborative networks are
some of the points that integrate these improvements, and “that
dramatically reduce development costs while accelerating the
learning curves of operations in Smart Cities”[16].
Still on the expansion of the Internet of Things, the concept
of Playable Cities comes as a counterpoint to the Smart Cities.
This new concept brings the idea of a city where citizens /
users, hospitality and openness (new relationships) are
fundamental, allowing its residents and visitors can reconfigure
and / or rewrite their services, places and stories. Within the
concept of Playable Cities, people and their relationships are
privileged, to the contrary the cold data of Smart Cities [14]. In
practice, it is a place of many possibilities of entertainment in
permanent construction.
It is exactly from the interactionist perspective, the social
construction of urban spaces, the present work brings with it
the challenge of growth, new possibilities, to the insertion of
new paradigms of performance in public spaces. Creating
games in urban centers necessarily puts the citizen/user as the
center of opportunities, making the cities scenarios of
possibilities. It is the emerging of IoT as participatory element
in the urban context, creating a dialogical context with existing
things in cities, making urban responsive objects, putting
“things” as new aesthetic possibilities of construction of
knowledge [1].
Finally, we need to reinforce the idea of new possibilities
for the use of public spaces, and inserting enablers of the
Internet of Things to (re) signification of urban spaces. The use
of NFC (and other pervasive media) in the context of games, in
which real-world objects would be tagged with this technology,
and mobile devices could interact with the information on these
labels. This possibility significantly expands the scope of
opportunities, including the notion of Playable or Ludic Cities.
Building a platform that supports the creation of new games,
new possibilities, taking into account the extent of urban
centers, it is necessary, just when the technology proves to be a
viable alternative for improving citizens’ quality of life.
III. THE TAG HUNT PLATFORM
The proposed environment for scavenger hunt game
construction and execution the interaction with objects from
the physical world, for instance, in a museum, in a public
square or in a shopping mall. Through a mobile phone, users
running a mobile application will be able to interact with the
IoT-powered objects (interaction elements) and gather
contextual information from that object that will be helpful for
the next step in the game. For instance, after scanning a
painting with a hidden NFC tag, the mobile application may
display information (i.e. a “clue”) to find the next interaction
element of the game, or simply provide access to more
information about the object (e.g., a link to a video, to a quiz,
to an image).
Since our initial experiment intended to evaluate user
engagement, two important requirements were taken into
account: (1) the application should reach as much phone
platforms as possible and (2) the game should be easy to play,
without many additional steps such as user registration or user
login. Therefore, we decided to go for a Web-based approach,
where no App installation would be required, and not including
any user information (e.g., anonymous players), thus fulfilling
both requirements. Due to that architectural choice of not using
an App, the implementation did not include Bluetooth
proximity, which would have to use the smartphone API.
An overview of the implementation is shown in Fig. 1,
where the numbered items are individually described below.
1. Web client of the games administrator
2. Android app for game management that lists the
available quests (i.e., a scavenger hunt) and allows the game
administrator to write the respective URLs of each tag
3. A smartphone that either scans the NFC tag or QR
Code containing a URL, which points to the Web Server
4. The REST API that allows the Android App to query
the server about the available quests and the respective game
steps (e.g., clues)
5. The PHP Web Server containing the business rules for
quest creation and game engine implementation
6. The database where the quest information and user
progress are stored.
Web$Server$
(PHP)$
REST$API$
DB$
User/player$
Administrator$
Read%
Write%
Request%
Request%
Request%
R/W%
2
3
1
45
6
Figure 1. TagHunt Platform architecture overview
To illustrate the flow of game creation, one can think of a
user that is responsible for accessing the administrative Web
application. This is the user interface for creating a scavenger
hunt game (i.e. a quest). For each quest, that user can add new
clues (i.e. steps). During game play, each clue corresponds to a
unique URL. After creating all the necessary clues, the user
(i.e. game administrator) can use a specific mobile application
(Android) that will interact with the Web sever and list the
available quests. After choosing a quest the application will
display a list of available clues. The App will give the option to
write the clue’s unique URL in an NFC tag, using Android’s
Advanced NFC API. When accessed during game play, the
clue URL will be displayed by the mobile-tailored Web
application as in the example of Fig. 2. Optionally, a user may
also access the system to generate the QR Code of a clue’s
URL.
Figure 2. Two screenshots of the Web-based client,
tailored to mobile phone screens
IV. EXPERIMENT
In order to validate the platform, we created four different
scavenger hunt games using the TagHunt platform. In each
game we collected information anonymously in two distinct
ways: implicit and explicit. The former approach concerned the
Web-based system gathering data around the progress of each
user in each game. The latter approach consisted of a
questionnaire applied to a subset of users after game
completion. The goals of the experiment were twofold: (1)
validating our platform by using it to create scavenger games
and (2) invite actual users to test games created with our
platform in order to evaluate the user experience.
Although the current implementation of the game would work
with both NFC and QR Code, the experiment focused on the
game usage exclusively with NFC tags as the IoT technology
for object hyperlinking. NFC tags were placed using two
different ways: either hidden behind thin objects (e.g., posters,
banners, signs) or sticked over visible objects (e.g., plastic trash
can, wall), as respectively illustrated in the left and right side
pictures contained in Fig. 3.
A. Experiment setting
The four games were divided in two different locations, in
distinct dates of July/2014. The first location was at the Centro
de Informática from UFPE university (+1500 graduate and
undergraduate students), where only one scavenger hunt was
conducted. The second location consisted of a three-day
technology festival (+4000 attendants), where simultaneous
talks, hackathons, game competitions and many other
technology related activities. This was Recife’s edition1 of a
festival that takes place in many cities around the world, being
held in the local convention center.
1 http://recife.campus-party.org/
1) First location: University
At this stage, we tested the system with a small sample group
of 31 subjects, who previously attended an informative lecture
about the Near Field Communication technology. Among
these, 15 (48.4%) were able to participate in the experiment
itself because the others did not have smartphones with NFC-
technology enabled.
Since this experiment was actually an initial test, the
audience was mostly people who had experience in learning
and handling of new technologies, and the organizers
monitored users during the experiment, helping individuals to
read the first six tags hidden around the test area.
In order to motivate the audience and possible users, it was
announced that everyone who achieve the main objective (to
collect all six hidden tags), in a certain time limit, they could
participate in a raffle for a ticket to a locally event about
technology.
2) Second Location: Convention Center
Three different experiments were performed on three days,
in a bigger area than the one performed at the first stage,
including a larger and more varied sample group.
a) Day 1
In the experiment of the first day in the convention center,
the users were previously instructed in a 30 minutes talk that
was part of the main event program. The talk focused on NFC
technology and the TagHunt game mechanics. During the talk,
as a way to stimulate user participation, the audience was
informed about mugs that would be offered as prizes for those
who completed the scavenger hunt. A total of 6 tags was spread
on the convention center pavilion.
b) Day 2
In the second day the scavenger hunt was announced
through social media, mentioning the gifts (mugs) offered as
prizes for those who completed the scavenger hunt. The
audience was invited to the same stage where the talk from the
previous day took place. This time a brief and more informal
talk just explained game mechanics, with little instruction on
NFC technology (e.g., how to enable it in the user’s phone).
All users had to collect eight tags, two more than in the
previous day.
c) Day 3
This time the scavenger hunt was announced again on
social media channels. This time the prizes were more
significant: three tablet computers and three gift cards
(approximately U$ 40) from a local bookstore. Another
difference from previous settings is that there was no previous
live interaction with the participants (face-to-face). Instead of
inviting people to a talk about NFC or TagHunt, users were
informed were the first clue was located. Again, there were
eight tags distributed along the test area.
Figure 3. Two screenshots of users playing scavenger hunt
games with NFC
B. Data
This section describes the data collected in the experiments.
Initially the population involved in the experiment is described,
followed by data concerning game completion. Finally, the
questionnaire is described along with the collected answers.
1) Population
The population of the experiment consisted of users
acquainted with technology. The university experiment
involved a total of 15 students from undergraduate and
graduate courses in the Computer Science domain. The
experiments conducted in the convention center had a more
diverse audience, with most of them technology enthusiasts,
since the main events being held consisted of technical talks
related to technology (robotics, programming, social networks,
etc). Table 1 summarizes all the population data. Although no
precise data was analyzed concerning smartphone models,
both Android and Windows Phone were observed as the most
popular models used by the players, with the exception of one
Blackberry model that participated in the first experiment.
Table 1. Population that participated in the experiments
Experiment
Game
participants
Questionnaire
participants
Age
average
(survey)
Std.
deviation
University
15
15
24.6
5.5
Convention
Center D1
35
22
21.9
4.0
Convention
Center D2
28
8
21.1
2.4
Convention
Center D3
38
11
24.1
5.5
2) Game Completion
In the University scenario we verified that only 10 users
(66.7%) in fact completed the proposed quest (initially started
with a group of 15 users). In the Convention Center (Day 1) we
started with 35 users and 19 (54.2%) underwent the
experiment. In the second day, the Convention Center (Day 2),
the experiment had 28 participants, and 9 of them (53.7%)
achieved the quest proposed. In the Convention Center (Day 3)
they were initially registered 38 users, and 9 (23.7%) ended up
collecting tags. These numbers are illustrated in Fig. 4, where it
can be noticed that experiments 3 and 4 had 8 tags while
experiments 1 and 2 involved the collection of 6 tags.
Figure 4. Total number users and how many tags they
collected in each one of the four experiments
3) Questionnaire
The questionnaire that was applied had 9 questions
answered according to a typical 5-step Likert scale (Strongly
agree, agree, neither agree or disagree, disagree, strongly
disagree):
Q1. The activities proposed by the game were clear and
the objectives were sufficient for performing such activities.
Q2. It was easy to find the NFC tags based on the game
information.
Q3. The information available in the smartphone was
readable and well positioned on the screen
Q4. During the game I felt motivated to execute the
proposed objectives.
Q5. I would use this game in a public space (e.g., in a
park, in my neighborhood, in my city)
Q6. The initial set of instructions (configuration of the
smartphone, how to read an NFC tag, among others) were
enough for the realization of the game activities.
Q7. The information provided in the game were enough to
execute the next step in the activities.
Q8. I felt comfortable in using NFC technology in games
or applications.
Q9. I would use again a game or application employing
NFC technology.
Q1 to Q3 were concerned with Ease of Adoption, Q4 an Q5
with perceived Value, Q6 and Q7 were related with Trust, and
Q8 and Q9 were focused Perceived Ease of Use. Since the
pattern was very similar for all experiments if their answers
were individually analyzed and compared among them, the
graphic in Fig. 5 considers answerers from all experiments
together.
!
Figure 5. Percentage of the five answers in the Likert scale
ranging from 1 (Strongly Agree) to 5 (Strongly disagree)
C. Discussion
The requirement indicating the application should reach as
much phone platforms as possible was indeed an important
choice that led to a Web-based approach. Such decision
allowed NFC-powered phones from both Android and
Windows phone platform to easily participate in the games
without any need to install specific applications. These choices
allowed a true “touch and play” scenario.
The attrition or bounce-rate, which indicate when users
give up, is visible in Fig. 4. It shows the stabilization between 4
and 6 collected clues (or tags). Experiments 3 and 4 show that
number starting to slightly decrease again on the 7th and 8th tag
being read. The graphic suggests that scavenger hunt games
with 4 to 6 tags to be the ideal quantity of clues to retain users
engaged. More investigation would be needed, since this
involves also other variables, such as the difficulty to find the
hidden tags (i.e. clues).
Fig. 5 helps understanding that fact. All of the questions
present over 60% of the responses as Strongly Agree, except
for Q2, which does not comply with that pattern. That question
concerns “Ease of adoption” being specifically about the
difficulty to find the NFC tags based on game information.
Around 30% of respondants Strongly Agree on that question,
and over 40% only agree, and 30% remained neutral. Typically
in the other questions, neutral responses were below 10%. We
also analyzed each experiment individually, and a very similar
pattern can be identified concerning Q2, which differs from the
other answers.
Another variable is important to be observed. The fact of
having instructions or not about how to play the game has
significant impacts on engagement. In experiment 4 users did
not have any instructions. This is the only experiment in which
there is a significant drop of users collecting tags. 38 uses
collected the first tag, but that number drops to half for those
who collected the second tag.
V. RELATED WORK
The work of Kranz et al. [8] tries to assess NFC popularity
through the usage of a game for Android smartphones. Users
download the App which allows them to scan random NFC
tags they found in their day-to-day. The authors employed
gamification to stimulate their users to collect tags and
accumulate points for each "collected" tag, with bonus points
for those that upload pictures of the tags, or when rare types of
tags were scanned.
Specifically focusing on scavenger games using NFC,
initiatives can be found mainly in industry, although such
approaches do not provide users with the ability to create their
own quests or scavenger games as we propose with TagHunt.
One example of such type of initiative is Google I/O Hunt[12],
which was played by attendees of the Google I/O event, in
2013, and later released as an open source project. By using an
Android App, players scanned NFC tags that provided clues for
the other tags. The goal of the game was find a hidden dog
called Alex. The player interacts with the game reading an
NFC tag or answering trivia.
Munzee[11] is a scavenger hunt game where is possible
looking for objects in the real world. The items are virtually
collected using smartphones. Using a gamification approach,
the player wins badges for the items (called munzees) they
collect, increasing their level. A munzee can be having
different shapes but it is equipped with an NFC tag or a QR
code. As part of the business model of the company behind
Munzee, they allow users to deploy their own munzees by
selling NFC tags or through printing (QR code).
The approach we found as a platform for game creation in a
pervasive computing scenario is rather based on frameworks
and APIs instead of allowing people that are not necessarily
programmers to construct their own games, which is our
proposition. Besides, such platform does not directly deal with
NFC. In fact, Placechallenge[13] rovides a platform for
location-based games supporting collaborative games and
competition among players. Two examples of applications built
on top of that platform are GetChi[4] and Runaway[15]. In
GetChi, players use a map to find the "Chi" places they need to
visit in order to collect them. In "Runaway" the user has to visit
the places where virtual coins are placed and wait a few
moments in order to collect them.
VI. CONCLUSIONS
Many IoT-related technologies are present in smartphones,
including NFC. We are motivated by the usage of object
hyperlinking to boost the usage of NFC, and alternatively QR
Code, by mixing object hyperlinking and scavenger hunt
games. This paper proposed a novel scenario for the IoT,
involving objects from the physical world in a digital game. In
such games, participants use smartphones to obtain data from
real world objects. The data will help users to be guided
through different steps in a scavenger hunt game. We brought
the notion of a platform for the creation of scavenger hunt
games employing object hyperlinking and performed the
evaluation of user engagement in those scenarios.
After performing four experiments in two different
locations, we could verify that a Web-based approach made
easy for users to participate in the scavenger hunt games using
the TagHunt platform, allowing a true “touch and play”
approach. After analyzing game data, we could verify that the
rate of users giving up the game would stabilize between 4 and
6 tags in a scavenger hunt. This number could be involved with
the difficulty to find the hidden tags, thus needing more
investigation. Another important factor observed is that,
although NFC is relatively simple to use, the absence of
instructions to users explaining how to play a scavenger hunt
game using NFC may significantly reduce the number of
players that would engage in the game, as it was verified.
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