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  <front>
    <journal-meta>
      <journal-title-group>
        <journal-title>ACM Hypertext Workshop, Prague, Czech
Republic, July</journal-title>
      </journal-title-group>
    </journal-meta>
    <article-meta>
      <title-group>
        <article-title>The Emergence of Crowdsourcing among Poke´ mon Go Players</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Priscila Martins</string-name>
          <email>primsouza@dcc.ufmg.br</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Fabr´ıcio Benevenuto</string-name>
          <email>fabricio@dcc.ufmg.br</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Manoel Ju´ nior</string-name>
          <email>manoelrmj@dcc.ufmg.br</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Jussara Almeida</string-name>
          <email>jussara@dcc.ufmg.br</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Federal University of Minas Gerais</institution>
          ,
          <addr-line>Belo Horizonte, Minas Gerais</addr-line>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2017</year>
      </pub-date>
      <volume>4</volume>
      <abstract>
        <p>Since its launching, Poke´mon Go has been pointed as the largest gaming phenomenon of the smartphone age. As the game requires the user to walk in the real world to see and capture Poke´mons, a new wave of crowdsourcing apps have emerged to allow users to collaborate with each other, sharing where and when Poke´mons were found. In this paper we characterize one of such initiatives, called PokeCrew. Our analyses uncover a set of aspects of user behavior and system usage in such emerging crowdsourcing task, helping unveil some problems and benets. We hope our eort can inspire the design of new crowdsourcing systems.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>
        INTRODUCTION
e mobile games industry experienced an exponential growth
in the past decade, motivated mainly by (i) an ever increasing
worldwide penetration of smartphones and mobile devices, (ii) the
ability of such devices to deliver quality audio and video; and (iii)
the increasing capacity of network transmissions of these devices,
allowing users to download larger and more complex games [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ].
      </p>
      <p>
        e largest gaming phenomenon of the smartphone age so far
has been the augmented reality game Poke´mon Go. It was launched
in July 2016, rstly in Australia, New Zeland, and USA. Yet, in
one week aer launching, it had already reached seven million
users, accounting for three to six times more downloads of the
most popular games in history at that time [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]. e game makes
use of GPS, camera, and position sensors of smartphones which
allow its users to capture, bale and train virtual creatures called
Poke´mons. ese creatures appear on the phone screen as if they
were in the real world. e set of technologies that allow this kind
of experience support the so-called augmented reality, a eld that
has received a lot of aention aer the game success.
      </p>
      <p>
        ere has been a number of recent studies exploiting behavioral
changes among Poke´mon Go players. Nigg et al. [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ] suggest that
Poke´mon Go may increase physical activity and decrease sedentary
behaviors. Other eorts [
        <xref ref-type="bibr" rid="ref2 ref3 ref8">2, 3, 8</xref>
        ] argue that the game may represent
a new shi in perspective: players tend to socialize more while
playing as they tend to concentrate in popular areas of the game,
oen called Poke´Stops.
      </p>
      <p>
        Since the game requires the user to walk in the real world to see
and capture the Poke´mons nearby, a new wave of supporting apps
has emerged. In these apps, players can collaborate with each other,
sharing where and when Poke´mons were found. ey represent
the emergence of a crowdsourcing eort of the game players to nd
rare and valuable Poke´mons. PokeCrew1, one such app of great
popularity, is a crowdsourced Poke´mon Go map. It shows reports
of locations of Poke´mon posted by players in real time in a map and
it became quite popular among the most active users. For example,
this website was ranked among the top 15000 domains in the Web,
according to Alexa.com [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] and its IOS and android versions had
hundreds of thousands downloads.
      </p>
      <p>
        In this paper, we characterize the crowdsourcing eort of Poke´mon
Players through PokeCrew. Crowdsourcing systems enlist a
multitude of humans to help solve a wide variety of problems. Over the
past decade, numerous such systems have appeared on the Web.
Prime examples include Wikipedia, Yahoo! Answers, Mechanical
Turk-based systems, and many more [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. Our eort consists in
characterizing an emerging type of crowdsourcing system, identifying
many interesting technical and social challenges. To that end, we
obtained a near two-month log of reports from the game players,
containing 39,895,181 reports of Poke´mon locations. Our analyses
uncover a set of aspects of user behavior and system usage in an
emerging crowdsourcing task. We hope our eort can inspire the
design of emerging crowdsourcing systems.
      </p>
      <p>In the following, we rst describe the data used in our study and
then analyze how users collaboratively help each other within the
Pokecrew platform. We nish this paper with our conclusions and
possible directions for future work.
2</p>
    </sec>
    <sec id="sec-2">
      <title>DATASET</title>
      <p>With the increasing popularity of Poke´mon Go in the whole world,
many applications emerged with the purpose of enhancing the
players experience with the game. Among the most popular ones
are Pokecrew2, PokeRadar3, and PokeVision4. e idea is to share
Poke´mon maps and their locations in a crowdsourced way: aer
nding Poke´mons in the game itself users may report them in the
supporting app, making the creatures visible to other players that
are not in that specic location and time. is can be very useful
to players, since, in the game, it is not possible to see Poke´mons far
from where the player is currently physically located.</p>
      <p>We have obtained data from Pokecrew, a popular app that oers
to users a map containing the location of Poke´mons reported by
other users. e application can be found in the PlayStore, AppStore,
as well as on the Web. Our dataset contains 39,895,181 reports,
from July 12th to August 24th 2016. Each report contains several
information elds, including: a report id, reported Poke´mon id,
geographic coordinates, time when the report was created and, in
some registers, a username.</p>
      <p>Our results show that most reports in our dataset (98.7%) do
not include a valid username, since the app does not require the
user to identify itself in order to create reports. us, although we
report general statistics computed over the whole dataset in the
next section, we focus on the subset of reports with valid usernames
to study user behavior. We note that, despite the small percentage,
there is still a considerable amount of identiable reports (over
500k) on which we can perform such analysis. Finally, we also
note that the spatial information in our dataset refers to geographic
coordinates of the reports.
3</p>
      <p>REPORTED POK E´MONS AND THEIR</p>
    </sec>
    <sec id="sec-3">
      <title>LOCATIONS</title>
      <p>We start our characterization by analyzing which Poke´mons are
the most reported ones and where they were reported. We then
discuss the application adoption on specic locations.
3.1</p>
    </sec>
    <sec id="sec-4">
      <title>Most Reported Pok e´mons</title>
      <p>Table 1 shows the top-10 most reported Poke´mons in our dataset.
We note that these Poke´mons are evolutions or dicult to nd in
the game. An evolution of a given Poke´mon consists of a similar
monster but with a higher power, which is very important to bale
with other Poke´mons in the so called ’gyms’, popular places across
the world where a user (a Poke´mon master) bales with other
users in order to take control of that gym. Besides that, having
these evolutions contributes to the user’s Pokedex, which is a list
containing detailed stats for every creature from the Poke´mon
games. e more Poke´mons a user has in her list, more experience
she has on the game, which is also important to bale with other
players at the gyms. Capturing an evolution is aractive to players
because the only alternative way to obtain them is to use an egg,
which is earned as the player progress in the game. With this
egg, the Poke´mon master can put it to crash, which is achieved
by walking. e distance required to crash an egg may vary (2,
2www.pokecrew.com
3hps://www.Pokemonradargo.com/
4www.pokevision.com
5 or 10 kilometers). e higher the distance, the more valuable
the Poke´mon that comes out of the egg is. us, it is much more
convenient to catch the evolved Poke´mon right away than it is to
walk waiting for the egg to crack and, luckily, be rewarded with a
powerful Poke´mon.</p>
      <p>is observation shows the great contribution of Pokecrew to
Poke´mon players: the interest in rare Poke´mons or evolutions is
what drive players to appeal to these crowdsourced apps. ese
Poke´mons are more valuable than the most commonly found, which
normally have less power to bale.</p>
      <sec id="sec-4-1">
        <title>Poke´mon’s Name Fearow Raichu Slowbro</title>
        <p>Golduck
Pidgeot
Nidoran
Tentacool
Nidoqueen
Magnemite
Clefable
We note that our dataset contains only geographic coordinates of
the reports. In order to characterize the location where these
reports were made, we rst converted the coordinates to the cities
and countries where the reports are made. Our approach to do
that consisted of using a reliable Python library, namely geopy5,
which allows us to retrieve the nearest town/city for a given
latitude/longitude coordinate.</p>
      </sec>
      <sec id="sec-4-2">
        <title>City</title>
        <p>New York City
San Francisco
Taipei
Paris
Santiago
Johor Bahru
Kuala Lumpur
Long Island City
Tokyo
Kampung Pasir
critical, since the adoption of Poke´mon GO was fast and user
engagement was very strong. In an application like Pokecrew, if the
user does not encounter Poke´mon reports, it is very likely she
will not be motivated to use the system and therefore won’t be
encouraged to create new reports.</p>
        <p>To assess whether the previous presence of Poke´mons in the
application inuences the user to create new reports, we compared
the amount of reports in a popular area among the days. To that
end, we focused on the reports in the city of New York, which
concentrates most part of reports. e city geographic area was
rst divided into 800 regions of approximately 500m2 , and for each
region we counted the total number of reports created on each day.
Besides that, we considered the period from August 14th to 26th ,
which concentrates a larger number of reports. It is possible to
see in Figure 1, most of the reports made in New York City, were
created in the Central Park area, a very popular place in the game
itself. Figure 2 shows a heat map correlating the number of reports
in each region showed in Figure 1 in each date.
Next, we provide a characterization of the crowdsourced Pokecrew
data, exploring aspects of user behavior and their engagement
within this crowdsourced system. e dataset collected presents
39,895,181 reports, but only 452,359 (1.3%) are registered users
(nonanonymous). We focus the next analysis on the behavior of this
identied group of users.
4.1</p>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>User Engagement</title>
      <p>Analyzing the reports made by registered users, we can notice
that some of them, mostly users who contributed with the largest
amounts of reports, reported a large number of sightings in just
one day. For example, the top 1 user reported 184,615 times, being
her reports concentrated between July 21st and 24th . Specically,
reported 13,007 times on July 21st and 75,574 on July 22nd , which
are very expressive numbers. Similarly, 31,656 reports made by the
second most active user, which corresponds to almost 99.7% of his
contribution to the Pokecrew system, were concentrated on a single
day, August 12th . e 10 most active users in the Pokecrew system,
in terms of reports of Poke´mon sightings, are shown in Table 3.
We note that some users have reported far many sightings than
others, especially the 4 most active ones. Given the large amount
of reports associated with these users, and the short time interval
during which they were made, we speculate that these reported
sightings may not have been made by “legitimate” Pokecrew users.</p>
      <p>Based on the amount of reports that the top 5 have made, and
the fact that these reports are, in general, concentrated in a few set
of days, we’ve disregarded this data for some analysis. Just a few
number of users have reported from 30 to 261 times. Most of users
have reported from 1 to 20 times. We have categorized users who
have reported from 1 to 5 times as less active users, representing
80% of the database.</p>
      <p>Given that for each report we have the information about the
time when it was created and its location, we can calculate for each
pair of reports of a single user the speed in which he would have
to dislocate in order to make both reports. Calculating the speed
for each pair of user’s report, we obtained a set of speeds from
the identied user’s reports. e chart bellow shows the speed
distribution across the total identiable users:</p>
      <p>As we can see in the plot above, a considerable number of reports
made by the users in the system reveal that they would have to
move at abnormally high speeds for this kind of game. Even if
we consider the case where a user report a Poke´mon in one place,
go on an airplane trip and then report another in the destination,
which although maybe uncommon, is possible, some speeds are not
feasible to achieve. e problem is that, even though the PokeCrew
app uses the GPS data from the smartphone and places the map
in the user current location, the player has the ability to move the
map to any place in the world and therefore report a sighting from
anywhere. ere is no validation in the app if the report being
created is trustful. is opens a serious aw in the system, because
malicious users and even bots could create fake sightings to spoof
the system and degrade the legit user experience. Even if the user
could not change the location in the map, it would still be possible
to report a Poke´mon that does not exist in the game itself at that
given time and location. is kind of validation is a key problem in
collaborative systems, and can be very challenging due to the lack
of mechanisms to control whether the information being supplied
to the database is true or not.
4.2</p>
    </sec>
    <sec id="sec-6">
      <title>Temporal Analysis</title>
      <p>e created at eld represents the date when the the sighting was
reported by a user. e chart below shows an analyse about how
many reports were made in each day. is scenario changes aer
August 8th , with a peak of reports on August 21st .
5</p>
    </sec>
    <sec id="sec-7">
      <title>CONCLUDING DISCUSSION</title>
      <p>is paper explores one out of a new wave of applications that
rely on collaborative databases in the mobile gaming environment.
Poke´mon Go was a huge phenomenon in this area and motivated
the creation of innumerable initiatives to enhance the gamers’
experience. Since the game requires the user to walk and visit places
in order to succeed at being a Poke´mon master, this kind of support
showed to be extremely useful to players, because they could go
straight to the exact location where a desired Poke´mon is located
instead of randomly walk hoping to nd some valuable monster,
as we could see with the most reported Poke´mons. One important
aspect in this work was to show how vulnerable such systems are
to spoofed data. Beyond the gaming environment, we can cite other
collaborative systems such as Wikipedia, where it’s possible to see
articles with dubious content, although they have more strict
controls to prevent these kind of activity. In the Pokecrew application,
inconsistent locations over time for some users and the noticeably
high amount of reports these users pushed to the system certainly
had a negative impact over the legit nal user experience, who
could encounter fake reports on the map. e recurrent presence of
fake data on crowdsourced applications can be very frustrating to
the nal user, who can be discouraged to continue using the system
and therefore stop providing useful information to the database.
One possible solution for the considered scenario would be add an
authentication layer to the system to detect and possibly ban users
spamming the system. Besides that, some metrics can be useful
to track abnormal activity, as we showed with the speed chart on
section 4. us, it’s highly recommended for collaborative systems
such as the application studied in this work to implement these
mechanisms to keep the system safe from unwanted data.</p>
    </sec>
    <sec id="sec-8">
      <title>ACKNOWLEDGMENTS</title>
      <p>We would like to thank Pokecrew for kindly sharing its data with
our research group and also the Sideways organization for the space
to spread this work. is work is supported by author’s individual
grants from Capes, Fapemig, and CNPq. F. Benevenuto is also
supported by Humboldt Foundation.</p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          [1]
          <string-name>
            <given-names>Pokecrew</given-names>
            <surname>Tra</surname>
          </string-name>
          c Statistics. (). hp://www.alexa.com/siteinfo/pokecrew.com Available at hp://www.alexa.com/siteinfo/pokecrew.com.
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          [2]
          <string-name>
            <surname>Fabio de Oliveira Roque</surname>
          </string-name>
          .
          <year>2016</year>
          .
          <article-title>Field studies: Could Pokemon Go boost birding</article-title>
          ?
          <source>Nature</source>
          <volume>537</volume>
          ,
          <issue>7618</issue>
          (
          <year>2016</year>
          ),
          <fpage>34</fpage>
          -
          <lpage>34</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          [3]
          <string-name>
            <surname>Leejiah</surname>
            <given-names>J Dorward</given-names>
          </string-name>
          , John C Miermeier, Chris Sandbrook, and
          <string-name>
            <given-names>Fiona</given-names>
            <surname>Spooner</surname>
          </string-name>
          .
          <year>2016</year>
          .
          <article-title>Poke´mon Go: Benets, Costs, and Lessons for the Conservation Movement</article-title>
          . Conservation Leers (
          <year>2016</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          [4]
          <string-name>
            <surname>Je</surname>
          </string-name>
           Howe.
          <year>2006</year>
          .
          <article-title>e rise of crowdsourcing</article-title>
          .
          <source>Wired magazine 14</source>
          ,
          <issue>6</issue>
          (
          <year>2006</year>
          ),
          <fpage>1</fpage>
          -
          <lpage>4</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          [5]
          <string-name>
            <given-names>Eddie</given-names>
            <surname>Makuch</surname>
          </string-name>
          .
          <source>Pokemon Go Reaches $600 Million, Faster an Any Mobile Game in History - Report</source>
          . (). hp://www.gamespot.com/articles/ pokemon-go-reaches-600
          <string-name>
            <surname>-</surname>
          </string-name>
          million
          <article-title>-faster-</article-title>
          <string-name>
            <surname>than-</surname>
          </string-name>
          any-mob/
          <fpage>1100</fpage>
          -6444687/ Available at hp://www.gamespot.com/articles/pokemon-go-reaches-600
          <string-name>
            <surname>-</surname>
          </string-name>
          millionfaster-than
          <string-name>
            <surname>-</surname>
          </string-name>
          any-mob/
          <fpage>1100</fpage>
          -
          <lpage>6444687</lpage>
          .
        </mixed-citation>
      </ref>
      <ref id="ref6">
        <mixed-citation>
          [6]
          <string-name>
            <surname>Claudio</surname>
            <given-names>R Nigg</given-names>
          </string-name>
          , Desiree Joi Mateo, and
          <string-name>
            <given-names>Jiyoung</given-names>
            <surname>An</surname>
          </string-name>
          .
          <year>2017</year>
          .
          <article-title>Poke´mon Go may increase physical activity and decrease sedentary behaviors</article-title>
          . (
          <year>2017</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref7">
        <mixed-citation>
          [7]
          <string-name>
            <surname>Jason</surname>
            <given-names>O. B.</given-names>
          </string-name>
          <string-name>
            <surname>Soh</surname>
            and
            <given-names>Bernard C. Y. Tan. 2008. Mobile</given-names>
          </string-name>
          <string-name>
            <surname>Gaming</surname>
          </string-name>
          .
          <source>Commun. ACM 51</source>
          ,
          <issue>3</issue>
          (March
          <year>2008</year>
          ),
          <fpage>35</fpage>
          -
          <lpage>39</lpage>
          . DOI:hps://doi.org/10.1145/1325555.1325563
        </mixed-citation>
      </ref>
      <ref id="ref8">
        <mixed-citation>
          [8]
          <string-name>
            <given-names>Masaru</given-names>
            <surname>Tateno</surname>
          </string-name>
          , Norbert Skokauskas, Takahiro A Kato,
          <string-name>
            <surname>Alan R Teo</surname>
          </string-name>
          , and Anthony PS Guerrero.
          <year>2016</year>
          .
          <article-title>New game soware (Poke´mon Go) may help youth with severe social withdrawal, hikikomori</article-title>
          .
          <source>Psychiatry Research</source>
          (
          <year>2016</year>
          ).
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>