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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Social Networks of Teachers in Twitter</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Hernán Gil Ramírez</string-name>
          <email>hegil@utp.edu.co</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Rosa María Guilleumas García</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>College of Education</institution>
          ,
          <addr-line>Carrera 27 #10-02, Barrio Alamos, Pereira, Risaralda (Colombia), ZIP code 660003</addr-line>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>College of Humanities and Fine Arts</institution>
          ,
          <addr-line>Carrera 27 #10-02, Barrio Alamos, Pereira, Risaralda (Colombia), ZIP code 660003</addr-line>
        </aff>
      </contrib-group>
      <fpage>43</fpage>
      <lpage>51</lpage>
      <abstract>
        <p />
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>This research aimed at identifying the trends
in the topics of interest of the tweets
published by 43 expert professors in the field of
ICT and education and the network of their
followers and followed in Tweeter, as well as
their relationship with the characteristics of
that network. With this purpose, NodeXL
was employed to import, directly and
automatically, 185.517 tweets which gave origin
to a network of connections of 49.229 nodes.
Data analysis involved social network
analysis, text extraction and text mining using
NodeXL, Excel and T-Lab. The research
hypothesis was that there is a direct correlation
between the trends identified in the topics of
interest and the characteristics of the network
of connections that emerge from the imported
tweets.Among the conclusions of the study
we can highlight that most of the trends
identified from the analyzed tweets were related
to education and educational technologies
that could enhance teaching and learning
processes; the association between education and
technologies found through the text mining
procedure applied to the tweets; and finally
that the analysis of lemmas seems to be more
promising than that of hashtags for detecting
trends in the tweets.
Currently, social networks in digital spaces are
an important part of the life of a good number of
people and institutions. Nevertheless, their study
poses important challenges for researchers, since
the huge volume of data circulating through them
implies -for collection, processing, and analysis-,
the use of specialized software, powerful
equipment, complex analysis methods, and qualified
people, items that are not always available in the
small and middle-size educational institutions.</p>
      <p>
        Though many users exchange through Twitter
what
        <xref ref-type="bibr" rid="ref4">Ferriter (2010)</xref>
        calls “digital noise,” this
researcher claims that professionals in education
have found ways to use Twitter to share
resources and provide a quick support to
colleagues with similar interests, turning this service
into a valuable source of ideas to explore.
      </p>
      <p>Twitter may be used for communication
purposes, but also to share information and build,
collectively, academic communities. This social
network enables interaction with other people,
access to their interests and identification of
trends from the published messages.
2</p>
    </sec>
    <sec id="sec-2">
      <title>Research background</title>
      <p>
        This work takes as referents some previous
research on Twitter and the generation, exchange
and propagation of information; it also considers
works about the influence of users on this digital
space.
        <xref ref-type="bibr" rid="ref11">Shneiderman (2011)</xref>
        explores the reasons
for the success of social media like Facebook,
Twitter, YouTube, Blogs, and the traditional
discussion groups and he concludes that it is due to
the fact that they allow people to participate
actively in local and global communities; the role
of Twitter as a communication resource and
information exchange tool during a crisis is tackled
in Herverin and Lisl (2010) research, and also in
        <xref ref-type="bibr" rid="ref3">Chew and Eysenback’s (2010)</xref>
        work.
      </p>
      <p>
        Wen
        <xref ref-type="bibr" rid="ref5">g, Lim, Jiang and He (2010</xref>
        ) focus on the
issue of the identification of the influential users
of Twitter;
        <xref ref-type="bibr" rid="ref1">Bakshy, Hofman, Mason and Watts
(2011</xref>
        ) study the features and relative influence
of Twitter’s users. Regarding the propagation of
information, our referents are Lerman and
        <xref ref-type="bibr" rid="ref5">Ghosh
(2010</xref>
        ), as well as the research carried out by
        <xref ref-type="bibr" rid="ref5">Gómez, Leskovec, and Krause (2010</xref>
        ), where
they state that the diffusion of information, and
viral propagation are fundamental processes in
the networks; we finally highlight the work done
by
        <xref ref-type="bibr" rid="ref13">Wu, Hofman, Mason and Watts (2011</xref>
        ), where
they stress the importance of understanding the
channels through which information flows, in
order to comprehend how it is transmitted.
3
      </p>
    </sec>
    <sec id="sec-3">
      <title>Theoretical considerations</title>
      <p>Castells (2011) thinks that the Internet is
revolutionizing communication thanks to its
horizontality, feature which permits users to create their
own communication network and to express
whatever they want, from citizen to citizen,
generating a capacity of massive communication,
not mediated by the traditional mass
communication media. This communication networks are
the basis of the “network society,” a concept
which was popularized by this author, who
describes it as the social structure that characterizes
the society of the early 21st century, a social
structure constructed around (but not determined
by) digital communication networks. (Castells,
2009, p.24). It is in the space and the time of the
network society where the studied group of
teachers constructs communication networks
using Twitter, making out of it more than just a
simple technology, a tool for communication,
encounter, and assistance.</p>
      <p>Castells defines a network as a set of
interconnected nodes. The nodes may have more or less
relevance for the network as a whole, so those of
higher importance are called “centers” in some
versions of the network theory. At any rate, any
component of a network (including the
“centers”) is a node, and its function and meaning
depend on the network programs and on its
interaction with other nodes in it. (2009, p.45) This
author explains that the importance of the nodes
in a network is higher or lower depending on
how much important information they absorb
and process efficiently, that is, it is determined
by their capacity to contribute to the
effectiveness of the network in the achievement of its
programmed objectives (values and interests).</p>
      <p>In this sense, we approach the study of the
communication networks created by teachers
from connections they establish in Twitter. In
this case, each user, and each web domain,
hashtag, lemma, constitutes a node which
establishes connections in the network under study,
where it is evidenced that there are nodes with
higher relevance than others. This is precisely
what contributes to the understanding of the
dynamics of these networks: what nodes are more
important in the network, which are their
contributions, and in what way they make up the
structures of these relationships.</p>
      <p>
        Social networks, as posed by
        <xref ref-type="bibr" rid="ref10">Lévy (2004)</xref>
        ,
provide tools for human groups to join mental
efforts so as to constitute intellects or collective
imaginaries. This allows for connecting
informatics to be part of a technical infrastructure of
the collective brain of lively communities, which
profit from social and cognitive individual
potentialities for their mutual development.
        <xref ref-type="bibr" rid="ref10">Lévy
(2004)</xref>
        describes collective intelligence as “una
inteligencia repartida en todas partes, valorizada
constantemente, coordinada en tiempo real, que
conduce a una movilización efectiva de las
competencias…” y agrega que “…el fundamento y el
objetivo de la inteligencia colectiva es el
reconocimiento y el enriquecimiento mutuo de las
personas (…)”.
      </p>
      <p>Concerning this point, we can sustain that
networks like Twitter create the suitable space to
integrate the intelligence of many people, located
in different places around the world; an
intelligence that is permanently updating, allowing
people linked to the network to widen their
horizons and possibilities to access information. Our
intent in this research is, following Lévy`s
pathway, to appraise the potential of Twitter as a
space for interaction in the network of the
teachers under study, and also to value the information
they exchange and which can be accessed
through this means, as a manifestation of
collective intelligence.
4</p>
    </sec>
    <sec id="sec-4">
      <title>Methodology</title>
      <p>This research followed a quantitative approach
with a trans-sectional, correlational,
nonexperimental design, which allowed for the
establishment of the relation between the trends in
the topics of interest detected and the structure of
the network of connections that emerged from
the tweets published by the selected group.</p>
      <p>In order to select the group to be studied, we
adapted the snowball sampling method. An
initial group of seven (7) professors was
intentionally identified and selected on the basis of their
academic background related to the use of the
ICTs in education, and their academic
contributions via the Internet, in particular through
Twitter. In a second phase, there was a follow-up of
these seven professors’ Twitter accounts, in
order to identify other teachers who followed them
or that they followed, and who, on the basis of
their contributions in Twitter, their publications
and academic output about the use of ICT in
education, could be part of the studied group. This
procedure was repeated once again until finally it
was formed, in a not probabilistic way, a group
of 43 teachers.</p>
      <p>Of the selected group, 65% were University
professors, 23% primary and secondary teachers
and 12% belonged to other type of institutions
(non-formal, virtual tutors and advisors).
Concerning their nationalities, 84% were from Spain,
7% from Argentina, 5% from Colombia, 2%
from Mexico and 2% from Venezuela.</p>
      <p>Using NodeXL we imported from Twitter,
185.517 tweets published by the network of
connections of the 43 selected teachers between
February the 4th and June the 6th, 2014.</p>
      <p>As data collection instruments, we used NodeXL
templates (which include not only the tweets but
also the information of the edges, as well as that
of the nodes). From the imported data rose a
network of connections made up 49229 nodes
and 98.494 edges.</p>
      <p>These nodes were located in 128 countries.
88.3% of them were concentrated in 10
countries, among them, Spain, Argentina, The United
States, Colombia, and Mexico. About one third
of the nodes registered in their profile
professions related with education.</p>
      <p>In order to identify the trends in the topics of
interest in the published tweets and their
relationship with the features of the network from
which they emerged, we made a graphic
representation of the network and calculated its
metrics, using NodeXL. Likewise, we identified the
trends in the topics of interest by analyzing the
imported tweets to quantify the frequencies of
appearance of the hashtags and by applying text
mining to the content of the tweets. We also
identified the trends in the web domains and
established the correlation among the frequencies
of the topics of interest detected as trends and the
metrics of the network, using multivariate
analysis, and Pearson’s correlation coefficient. For
data analysis we used the programs NodeXL,
Excel, T-Lab and Statgraphics.
5</p>
    </sec>
    <sec id="sec-5">
      <title>Analysis and data interpretation</title>
      <p>For data analysis and interpretation, we
examined the features of the network of connections
of the 43 teachers selected. Besides, based on the
tweets published by the mentioned network, we
identified the trends in the topics of interest and
studied their correlation with the values obtained
in the two previous steps.
5.1</p>
    </sec>
    <sec id="sec-6">
      <title>Features of the communication network</title>
      <p>We used NodeXL to make the graph of the
network of connections as well as to calculate its
metrics.</p>
      <p>Taking a look at figure 1 with its 49.229 nodes
and 98.494 edges, it is evident that, given their
location, not all the nodes have the same
importance in the network. A representative group
of nodes, located in the center, are the most
connected; a significant amount, the least connected,
are displaced outwards, and a couple of them,
though connected to each other, are disconnected
from the network.</p>
      <p>Figure 2. Communication network emerging
from the imported tweets, filtered.</p>
      <p>Figure 2 corresponds to the same network after
the application of a filter based on the
Betweenness Centrality index of the nodes and it shows
only those with a value higher than 1 for that
index. This produced a reduction of the network to
8.725 nodes (a 17.7% of the total). This process
allowed us to note, more clearly, the set of nodes
that occupied the center, while in the periphery,
in opaque tones, there can be seen the remaining
nodes, those out of the established filter.</p>
      <p>Thus, we can see the configuration of a
network, that as Castells sustains (2009:45), is made
up of interconnected nodes; some, the so-called
centers, of greater importance for the network,
and others, less important, depending on their
capacity to access information and process it
efficiently; that is, on account of their capacity to
contribute to the achievement of the objectives of
the network itself.</p>
      <p>The process of analysis implied, likewise, the
calculation of the graph’s metrics, as a basis for
the quantitative measurement of the indices
associated to the nodes and their edges. The graph is
directed. The relation of reciprocity of the edges
is of 0.27. The In-Degree ranges between 0 and
3.439, the Out-Degree between 0 and 1.789 and
the Betweenness Centrality index between 0.0
and 354805308.32.</p>
      <p>Of the 49.229 nodes analyzed, the 10 nodes
with a higher In-Degree, Out-Degree, and
Betweenness Centrality, belonged to the initial
group of 43 teachers selected. This shows that, in
addition to a relative high level of edges between
the nodes of the network, the initial group of 43
teachers selected, from which the network of
connections emerged, had a significant weight
within the network, both for the amount of nodes
connected to them as for the amount of nodes to
which they were connected and therefore for
their intermediation potential in the network.
This is particularly important in a scenario where
just a few nodes had high degrees of
intermediation.</p>
      <p>The 49.229 nodes of the network were
organized in 24 groups of diverse sizes, according to
the number of nodes in them. There was a high
amount of edges inside each group, as well as
among the different groups. For instance, group
1 had 8.220 nodes (16.7% of the total) and
174.397 edges. At the other end in size and edges
were group 23 (with 525 nodes, 1.1% of the total
and 586 connections) and group 24
(disconnected from the network, with just 2 nodes and a
single edge between them).</p>
      <p>Regarding the making up of the groups, we
want to state that within a network of
connections it is difficult to establish groups as well as
their precise borders since the nodes can be
involved in different relations and belong to more
than one group.</p>
      <p>In this research, the clusters were conformed
with NodeXL, using the
Clauset-NewmanMoore algorithm for clusters, that automatically
identifies the groups from the network structure,
placing the densely connected nodes in separated
groups; that is, conforming each group with a set
of nodes that are more connected to one another
than what they are to other nodes.</p>
      <p>On average, each of the 24 groups had 2.051
nodes, 2.939 inner edges and was connected to
21 of the 24 existing groups through 1.164 edges,
what shows a highly connected network. In this
respect, it is worth noting the existence of groups
that were rather highly connected to other
groups, as for example, group 1 with 5.678
edges, and group 2 with 3.076.</p>
      <p>
        We believe that the communication that exists
among the nodes, inside the conformed groups
and among them, facilitates the access to
information and its distribution inside the studied
network, thanks to what
        <xref ref-type="bibr" rid="ref2">Castells (2001)</xref>
        calls the
process of horizontality, which allows all the
nodes connected to the network to communicate
massively, to share whatever they wish and thus
build their communication networks, in this case
through the use of Twitter.
      </p>
      <p>As a summary, we can affirm that the network
studied was decentralized, though not in the
classic sense of the term since some nodes were
connected to one or more central nodes, which in
turn were often connected to several nodes,
central or not, making the structure of this network
more complex and robust, in such a way that if
one of the central nodes were to disappear, this
would not cause the disconnection of a great
amount of nodes or the disappearance of the
network.</p>
      <p>The study of the tweets exchanged in the
studied network showed that, within it, the identified
trends (hashtags, lemmas and web domains)
were the origin of other networks.
5.2</p>
    </sec>
    <sec id="sec-7">
      <title>Identification of tendencies of the topics of interest to be published</title>
      <p>The web domains referenced in the tweets, as
well as the hashtags and slogans more used, led
to the identification of the trends in the topics of
interest to be published in the studied network.</p>
    </sec>
    <sec id="sec-8">
      <title>Tendencies identified from the hashtags referenced in the tweets.</title>
      <p>Of the 185.517 imported tweets, 31, 5% (58.349)
included hashtags. The total of referenced
hashtags was 88.798, out of which 29.590 were
unique hashtags. We identified the hasthtags
referenced in the tweets and calculated their
frequency of appearance. The 10 hashtags with a
higher referencing frequency (0.03% of the total)
were used 6% of the times, while the remaining
29.590 (99.97%) appeared the 94% of the times.
The first place was for the hashtag #educación,
followed by #ABPmooc_intef and #elearning,
#tic, #edtech, #educacion, #eduPLEmooc, among
others.</p>
      <p>The ten hashtags with a higher frequency of
use in the tweets could be grouped around three
main topics: education (8 hashtags), politics (1
hashtag), and technology (1 hashtag). The
predominance of the hashtags related to the topic of
education could seem obvious in a network
initially composed by teachers; however, we should
remember that the 43 initially selected teachers
were the seed of a network that was enlarged to
include 49.299 nodes; this suggests that the 43
teachers followed and were followed either
mainly by teachers, or by people interested in
and concerned about education.</p>
      <p>
        This piece of data may show some degree of
homophily in the studied network of
connections, since despite the fact that Twitter users are
not forced to correspond to their followers
(directed network) and most of the links are not
corresponded, the users tend, however, to connect to
others exhibiting interests and activities similar
to their own
        <xref ref-type="bibr" rid="ref3 ref8 ref9">(Kwan, Lee, Park, and Moon, 2010)</xref>
        .
This situation also matches Wu, Hofman, Mason
and Watts’s findings (2011), who highlight the
significant homophily found in their research.
      </p>
    </sec>
    <sec id="sec-9">
      <title>Network of tendencies identified from the 10 most referenced hashtags</title>
      <p>The tendencies identified from the 10 most
referenced hashtags enabled the conformation of a
network of connections between the nodes
referencing the hashtags (source node) and the
hashtags which were being referenced (target
node).
Figure 3 illustrates how most of the connections
were grouped around a specific hashtags. There
are very few cases in which a node used more
than one hashtag. However, as an example of this
case, we can mention #eduPLEmooc y
#ABPmooc_intef, which set up some connections with
the same users.</p>
      <p>Figure 4 was the result of the application of a
filter based on the Betweenness Centrality index
of the nodes. It shows the 154 nodes (8.2% of the
total) with a higher than the average value of this
index. This process allowed the visualization of
those nodes with greater force of intermediation
in the network, located in the central part of the
graphic. It also let us observe that most of them,
about 91.8% have a low or no force of
intermediation at all. These nodes, represented with
opaque tones, were located in the periphery of
the graphic according to the decreasing value of
the index, a value that reached 0 for 1.533 nodes,
that is, for the 81.3%.</p>
      <p>As we can observe from these metrics, there
was an important number of nodes which could
be considered as “lurkers” since they do not
contribute much to the network; they are mainly
silent participants.</p>
      <p>The In-Degree index in this network ranged
between 0 and 335, the Out-Degree between 0
and a 6; and the Betweenness Centrality between
0 and 1.453.757,65. Although a hashtag can
receive many entries (as in the case of #educación,
with an In-Degree of 335, or #ElReyAbdica,
with 237), these are generated by many nodes.
We can then assert that the tendencies detected
are actually a product of the individual
contributions of an important number of network nodes,
what evidences the materialization of Lévy’s
collective intelligence.</p>
      <p>Within the network of connections of the 10
hashtags with a higher frequency of use in the
tweets, 21 groups were conformed. On average,
each group connected only to 2 other groups, and
there were even some groups that were not
connected to any. It is remarkable that the groups
with a larger number of nodes connected to a
greater amount of groups. One example of this is
Group 1, which having 271 nodes, was
connected to 5 groups. In contrast, the groups with a
lower number of nodes showed the tendency of
not setting up connections to any group. This
was the case of group 21, which having 2 nodes,
did not connect to any group.</p>
    </sec>
    <sec id="sec-10">
      <title>Trends identified in the lemmas of the tweets</title>
      <p>In order to advance in the identification of the
topics of interest in the tweets published by the
network of connections of the group of selected
teachers, we resorted to text mining. The analysis
of the content of the tweets was done with
TLab, using the automatic lemmatization (word
grouping) and the selection of key words.</p>
      <p>Starting from the 185.517 imported tweets, the
corpus of analyzed data was made up of 175.122
elementary contexts (EC), 179.374 words,
162.072 themes, and 2.574.255 occurrences. The
program automatically selected the 500 words
with the higher level of occurrence in the corpus,
out of which the non-meaningful terms were
manually deleted later (articles, preposition, etc.)
giving a remainder of 310 items. For text
segmentation (elementary contexts), we used the
paragraph, which in this case was equivalent to a
tweet. For the selection of key words we
employed the method of occurrences.</p>
      <p>Nº
1
2
3
4
5
6
7
8
9
10</p>
    </sec>
    <sec id="sec-11">
      <title>Lemmas</title>
      <p>Educación
Nuevo
Educativo
Social
Aprender
Curso
Seguir
Blog
Stories
Vida</p>
      <p>EC
4.024
2.543
2.415
2.404
2303
2.238
2.201
2.143
2.117
2.063
Lemmas associated with education, such as
educación, educativo, aprendizaje or curso stood out
in frequency of citation in the tweets as shown in
Table 1. The lemma educación had already been
identified as one of the 10 most referenced
hashtags.</p>
    </sec>
    <sec id="sec-12">
      <title>Analysis of co-occurrences/word associations</title>
      <p>The co-occurrence is the number of times
(frequency) that a lexical unity (LU) appears in the
corpus or within the elementary contexts (EC), in
this case in the tweets. The function word
association was used to detect which words, in the
elementary contexts, were the co-occurrences
with the lemma educación.</p>
      <p>The lemma Education, found in 4.024 of the
175.122 elementary contexts (EC) analyzed, was
associated to a group of lemmas, considered as
relatively close, among them tic, technology.
Their relation with the lemma educación is
confirmed by the higher values of the index of
association presented in Table 2. Tic, 0.166:
technology, 0.166. The closer the association between
two lemmas, the higher the coefficient.</p>
      <p>Table 2 presents data of the relationships
between occurrences and co-occurrences of the
lemma educacion in the elementary contexts.</p>
      <p>LEMMA
(B)
tic
tecnología
congreso
básico
innovación
ciencia
infantil
futuro</p>
    </sec>
    <sec id="sec-13">
      <title>Blog</title>
      <p>COEFF
0,166
0,166
0,109
0,107</p>
      <p>0,1
0,082
0,076
0,065
0,065
In addition, the lemma tic appeared in 1.577
elementary contexts, and the lemmas educación
and tic were referenced together in 419
elementary contexts. As we can observe in Tables 1 and
2, there was evidence of the prevalence of
lemmas associated with education, as well as of the
close association between them, in the
elementary contexts analyzed.
1 Conventions: LEMMA A= Educación; LEMMA B =
Lemmas associated with LEMMA (A); COEFF = Value of
the index of association selected; E.C. (AB) = Total of EC
in which the lemmas “A” and “B” are associated
(cooccurrences).</p>
    </sec>
    <sec id="sec-14">
      <title>Tendencies of the web domains identified in the tweets</title>
      <p>Out of the 185.517 imported tweets, 59,4%
included references to web domains. Using Excel,
113.361 domains were identified, out of which
18.448 were unique web domains. In order to
detect the tendencies in the domains, we
calculated their frequency of reference and located the
10 with the highest levels of reference. It is
worth noting the great amount of references
accumulated by these 10 domains, since making up
just for a 0.05% of the amount of unique
domains found in the tweets, they were referenced
in the 25,4% of the occasions.</p>
      <p>Among the 10 most cited web domains were
blog sites (blogspot, 1st position), sites for video
publishing (Youtube, 2nd position); social
networks (Facebook, 3rd position; Instagram, 6th
position; LinkedIn, 7th position; Foursquare, 9th
position); online newspapers and journals (Paper.li,
5th position; eldiario.es, 10th position); content
curation sites (Scoop.it, 4th position).</p>
      <p>It should be highlighted that most of the
referenced domains (4 out of 10) were social network
applications. Likewise, we must point out the
importance of the blogs for the studied network,
since besides the tweets that included mentions
to blogs of blogspot, there was also a
considerable amount of domains making reference to other
blogs, like in the case of blogs.elpais,
blog.educalab, blog.tiching,
blog.fernandotrujullo and blogthinkbig.</p>
      <p>This listing of web domains in general and
blogs in particular, permits the visualization of
tendencies in the use of the web, and may help
teachers approach the best possibilities to explore
them and integrate them in their teaching
practices.</p>
    </sec>
    <sec id="sec-15">
      <title>Network of the tendencies of the web domains identified in the tweets.</title>
      <p>The 10 domains more cited in the tweets allowed
shaping a network of connections between these
10 web domains (target nodes) and the users
referencing them (source node). This new network
was made up of 10.900 nodes and 28.745
connections (7.319 unique connections and 21.426
duplicated connections).</p>
      <p>To facilitate the analysis and interpretation of
the graph, we applied a filter based on the
Betweenness Centrality Index of the nodes,
allowing the visualization of the nodes with a higher
power of intermediation in the network, and
therefore, with a greater significance in so far as
the flow of information.</p>
      <p>Figure 5 shows the 1.397 nodes (about 12.8%
of the total) with a higher than the average value.
These were the small group of nodes located in
the center of the graph. These nodes may be
crucial in the flow of information, since they lied in
the paths between other nodes in the network and
therefore provided a link between them.</p>
      <p>Toward the periphery, in opaque tones, we can
see the remaining nodes, the ones left outside by
the applied filter. The great majority of them had
a low Betweenness Centrality index, that reached
0 for 9.295 nodes, that is, for the 85.3%. These
values reflect a distribution of Pareto, in which a
small number of nodes (about 13%) displayed
the higher values of Betweenness Centrality,
while a great number of nodes (87%) showed
relatively low values in this index.</p>
      <p>The In-Degree Index of this network had a
minimum value of 0 and a maximum of 3.367;
The Out-Degree presented a minimum of 0 and a
maximum of 6; the Betweenness Centrality
showed a minimum of 0 and a maximum of
56149284,89. These metrics evidenced a
higher maximum value of In-Degree than of
OutDegree, what indicates that though a web domain
may have been referenced many times (as the in
the case of Youtube, with an In-Degree of
3.367), these references were done by many
nodes. In other words, we can assert that the
detected tendencies were actually a product of
Lévy’s collective intelligence, and not of reduced
groups of nodes that fostered a particular interest.</p>
      <p>Nine groups were configured inside the
connection network of the 10 domains with the
highest frequencies of appearance in the tweets.
Group 1, despite being the most numerous, did
not connect to any other groups, though other
groups did connect to it. On average, each group
established connections with five other groups;
the average amount of nodes by group was 1.211
and that of the unique connections, 704.</p>
      <p>We must highlight that the groups with a lower
amount of nodes established connections with a
greater amount of groups, to the point that
groups 8 and 9 were connected to 8 of the 9
groups configured, while the groups with a
greater amount of nodes –groups 1 and 2- were
connected to less groups (0 and 1 group
respectively). This could mean that a great number of
the network nodes posted tweets referencing a
particular web domain, while a minority of them,
referenced in their tweets a greater variety of
web domains.</p>
    </sec>
    <sec id="sec-16">
      <title>Correlation between tendencies and metrics of</title>
      <p>the communication network.</p>
      <p>In order to correlate the six (6) variables
associated with the network of connections under
study, we applied a multivariate analysis, relating
pairs of variables of the metrics with the
frequencies of the identified trends. The variables of
the metrics were: In-Degree, Out-Degree, and
Betweenness Centrality. The variables of the
tendencies were: web domains (URL), hashtags,
and lemmas.</p>
      <p>URL</p>
    </sec>
    <sec id="sec-17">
      <title>Hashtag</title>
    </sec>
    <sec id="sec-18">
      <title>Lemma In</title>
    </sec>
    <sec id="sec-19">
      <title>Degree</title>
      <p>0,1627
0,0466
0,1961
Out</p>
    </sec>
    <sec id="sec-20">
      <title>Degree</title>
      <p>0,172
0,054
0,201</p>
    </sec>
    <sec id="sec-21">
      <title>Betweenness</title>
    </sec>
    <sec id="sec-22">
      <title>Centrality</title>
      <p>0,146
0,0454
0,1833</p>
      <p>As shown in Table 3, in most of the relations
between pairs of variables of the metrics and the
tendencies of the topics of interest, we found a
direct correlation, though weak.</p>
      <p>The highest correlation was observed between
lemmas and metrics, and the lowest between
hashtags and metrics. In the first case, the
highest correlation occurs between lemmas and
outdegree, followed by lemmas and in-degree.
6</p>
    </sec>
    <sec id="sec-23">
      <title>Conclusion</title>
      <p>The methodological procedure used in this
research allowed us to create a wide network of
users interested in education starting from an
initial group of 43 teachers.</p>
      <p>Although the nodes of the initial group
registered high values in the network metrics, their
influence in the identified trends was low.</p>
      <p>Most of the trends identified from the analyzed
tweets were related to education and educational
technologies that could enhance teaching and
learning processes, as for instance, blogs, social
networks as platforms for sharing documents and
other resources, online journals and curation
tools.</p>
      <p>It stands out the association between education
and technologies found through the text mining
procedure applied to the tweets.</p>
      <p>The importance of blogs as a trend was
confirmed by its appearance among the web
domains with the highest frequency of references in
the tweets.</p>
      <p>The direct correlation found particularly
between the metrics of the network and the trends
in the lemmas found in the analysis of the tweets,
allows to conclude the importance of analyzing
with particular attention the tweets published by
users with a higher out-degree since they seemed
to influence more the trends that arise from the
studied network.</p>
      <p>The analysis of lemmas seems to be more
promising than that of hashtags for detecting
trends in the tweets.</p>
      <p>Since nearly 6 of each 10 tweets included a
reference to a web domain, it would be interesting
to be able to explore in a greater detail, what is
what users are actually referencing through those
web domains.</p>
      <p>The results of this research and their usefulness
for identifying trends in the topics of interest of
educational professionals suggest we continue
exploring the possibilities of social networks and
the analysis of big data in the shaping academic
communities.</p>
    </sec>
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