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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Early Detection and Forecasting of Research Trends</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Angelo Antonio Salatino</string-name>
          <email>angelo.salatino@open.ac.uk</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Knowledge Media Institute, The Open University</institution>
          ,
          <country country="UK">United Kingdom</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>Identifying and forecasting research trends is of critical importance for a variety of stakeholders, including researchers, academic publishers, institutional funding bodies, companies operating in the innovation space and others. Currently, this task is performed either by domain experts, with the assistance of tools for exploring research data, or by automatic approaches. The constant increase of research data makes the second solution more appropriate, however automatic methods suffer from a number of limitations. For instance, they are unable to detect emerging but yet unlabelled research areas (e.g., Semantic Web before 2000). Furthermore, they usually quantify the popularity of a topic simply in terms of the number of related publications or authors for each year; hence they can provide good forecasts only on trends which have existed for at least 3-4 years. This doctoral work aims at solving these limitations by providing a novel approach for the early detection and forecasting of research trends that will take advantage of the rich variety of semantic relationships between research entities (e.g., authors, workshops, communities) and of social media data (e.g., tweets, blogs).</p>
      </abstract>
      <kwd-group>
        <kwd>Scholarly Data</kwd>
        <kwd>Research Trends</kwd>
        <kwd>Trend Detection</kwd>
        <kwd>Trend Forecasting</kwd>
        <kwd>Semantic Web Technologies</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>The research environment evolves rapidly: new potentially interesting research areas
emerge regularly while others fade out, making it difficult to keep up with such
dynamics. The ability to recognise important new trends in research and forecasting
their future impact is however critical not just for obvious stakeholders, such as
researchers, institutional funding bodies, academic publishers, and companies operating
in the innovation space, but also for any organization whose survival and prosperity
depends on its ability to remain at the forefront of innovation.</p>
      <p>
        Currently, the task of understanding what the main emergent research areas are and
estimating their potential is usually accomplished by experts with the help of a
number of systems for making sense of research data. Systems such as Google Scholar,
FacetedDBLP [1] and CiteSeerX [
        <xref ref-type="bibr" rid="ref1">2</xref>
        ] provide good interfaces which allow users to
find scientific papers, but they do not directly support identification of research
trends. Other tools such as Microsoft Academic Search, Rexplore [
        <xref ref-type="bibr" rid="ref2">3</xref>
        ], Arnetminer [
        <xref ref-type="bibr" rid="ref3">4</xref>
        ],
and Saffron [
        <xref ref-type="bibr" rid="ref4">5</xref>
        ] provide a variety of visualizations that can be used for trend analysis,
such as publication trends and co-authorship paths among researchers. However, the
manual detection of research trends is an intensive and time-consuming task.
Moreover, the constant increase in the number of research data published every year makes
the approach based on human experts less and less feasible. It is thus important to
develop automatic and scalable methods to detect emerging research trends and
estimate their future impact.
      </p>
      <p>
        Currently, there are a number of approaches for detecting topic trends in a fully
automatic way [
        <xref ref-type="bibr" rid="ref5 ref6">6,7</xref>
        ]. These are usually based on the statistical analysis of the impact of
certain labels associated with a topic. However, these tools are unable to take full
advantage of the variety of research data existing today and need to examine a
significant number of years (e.g., 3-4) before they are able to identify and forecast topic
trends [
        <xref ref-type="bibr" rid="ref7 ref8">8,9</xref>
        ]. In addition, they are only able to identify topics that have been explicitly
labelled and recognized by researchers [
        <xref ref-type="bibr" rid="ref9">10</xref>
        ]. However, it can be argued that a number
of topics start to exist in an embryonic way, often as a combination of other topics,
before being officially named by researchers. For example, the Semantic Web
emerged as a common area for researchers working on Artificial Intelligence, WWW
and Knowledge-Based Systems, before being recognized and labelled in the 2001
paper by Tim Berners-Lee et al. [
        <xref ref-type="bibr" rid="ref10">11</xref>
        ].
      </p>
      <p>The doctoral work presented here aims to solve the aforementioned limitations and
produce a novel approach to detect and forecast research topics. This approach will be
based on two main intuitions. First, I believe that by analysing the various dynamics
of research it should be possible to detect a number of patterns that are correlated with
the creation of new embryonic topics, not yet labelled. For example, the fact that a
number of authors from previously unrelated research communities or topics are
starting to collaborate together may suggest the emergence of a new interdisciplinary
research area. Secondly, I theorize that taking into account the rich variety of semantic
relationships between research entities (e.g., authors, workshops and communities)
and analysing their diachronic evolution, it should become possible to forecast a topic
impact in a much shorter timescale, e.g., 6-18 months. This holistic and
semanticbased analysis of the research environment is today made possible by the abundance
of both scholarly data and other sources of evidence about research, including social
networks, blogs, and so on.
2</p>
    </sec>
    <sec id="sec-2">
      <title>Relevancy</title>
      <p>In many real-world contexts, being aware of research dynamics can bring significant
benefits. Researchers need to be updated regularly on the evolution of research
environments because they are interested in new trends related to their topics and
potentially interesting new research areas. For academic publishers or editors knowing in
advance new emerging topics is crucial for offering the most up to date and
interesting contents. For example, an editor can gain a competitive advantage by being the
first one to recognize the importance of a new trend and publish a special issue or a
journal about it. Institutional funding bodies and companies need also to be aware
of research developments and promising research trends. Thus, an automatic approach
to detect novel topics and estimate their potential will bring significant advantages to
a variety of stakeholders. Indeed support for this PhD project comes from
SpringerVerlag, which is a global publishing company.</p>
    </sec>
    <sec id="sec-3">
      <title>Related work</title>
      <p>
        Several tools and approaches for the exploration of scholarly data already exist. From
the perspective of topic trend detection, we can classify these systems as either
semiautomatic or fully automatic. In particular, some systems for exploring the publication
space provide implicit support for semi-automatic trend detection, such as Google
Scholar, FacetedDBLP [1] and CiteSeerX [
        <xref ref-type="bibr" rid="ref1">2</xref>
        ]. Other systems offer instead an explicit
support for semi-automatic trend detection, like Arnetminer [
        <xref ref-type="bibr" rid="ref3">4</xref>
        ], Microsoft Academic
Search (MAS), Saffron [
        <xref ref-type="bibr" rid="ref4">5</xref>
        ] and Rexplore [
        <xref ref-type="bibr" rid="ref2">3</xref>
        ]. However, while all these systems are
able to identify and visualize historical research trends, they do not provide any
support for the detection of future ones.
      </p>
      <p>
        In the context of providing a fully-automatic way to detecting topic trends, many
approaches assess the impact of a topic by simply using the number of publications or
patents directly associated with it. For example, Wu et al [
        <xref ref-type="bibr" rid="ref7">8</xref>
        ] integrate bibliometric
analysis, patent analysis and text-mining analysis in order to detect research trends.
Some models also take in consideration the citation graph. For example, Bolelli et al.
[
        <xref ref-type="bibr" rid="ref5">6</xref>
        ] propose an author-topic model to identify topic evolution and then they use
citations to evaluate the weight for the main terms in documents. He et al. [
        <xref ref-type="bibr" rid="ref6">7</xref>
        ] combine
Latent Dirichlet Allocation and citation networks for detecting topics and understand
their evolution. However, these approaches are able to detect trends only after the
associated research areas are already established and they do not provide any support
to the early detection of research trends.
      </p>
      <p>
        State of the art methods for forecasting trends in research take usually into
consideration the number of publications and authors associated with a topic [
        <xref ref-type="bibr" rid="ref11">12</xref>
        ], or the
probability distribution of a topic over time [
        <xref ref-type="bibr" rid="ref12">13</xref>
        ]. They then analyse these time series
either by means of statistical techniques [
        <xref ref-type="bibr" rid="ref9">10</xref>
        ] or machine learning methods [
        <xref ref-type="bibr" rid="ref13">14</xref>
        ],
yielding a prediction for the following years. However, these methods do not take
advantage of the knowledge that can be extracted by analysing the dynamics of multiple
research entities (e.g., communities, venues), and they ignore the growing mass of
research data that today can be acquired from social networks.
      </p>
      <p>
        Another important aspect that needs to be taken into account is how to represent a
topic. In literature, several ways to define a topic model can be found. The first is
characterised by the use of keywords as proxies for research topics. Systems like
MAS and Saffron [
        <xref ref-type="bibr" rid="ref4">5</xref>
        ] use this kind of model. This approach has several drawbacks
because it does not take in consideration the relationships among research topics [
        <xref ref-type="bibr" rid="ref14">15</xref>
        ]
and keywords tend to be noisy. The second kind of approach is the probabilistic topic
model. Latent Dirichlet Allocation [
        <xref ref-type="bibr" rid="ref15">16</xref>
        ], which treats a document as a mixture of
topics and a topic as a distribution over words, is the most popular of these methods.
However, this model assumes that the topics used to generate a document are
uncorrelated, which may be a risky assumption for research topics [
        <xref ref-type="bibr" rid="ref16">17</xref>
        ]. Other approaches for
probabilistic topic model try to deal with this problem introducing a separability
condition [
        <xref ref-type="bibr" rid="ref17">18</xref>
        ]. A third solution is using an explicit semantic topic model [
        <xref ref-type="bibr" rid="ref16 ref2 ref8">9,17,3</xref>
        ], which
exploits a semantic network of research areas linked by semantic relations. The
advantage of this solution is that it goes beyond the use of noisy, uncorrelated keywords
and exploits instead an ontology of research areas.
      </p>
    </sec>
    <sec id="sec-4">
      <title>Research Questions</title>
      <p>Considering the gaps identified in the previous section, the main research question of
the PhD will be: “How is it possible to detect the early emergence of new research
topics and forecast their future impact?”.</p>
      <p>This question entails two different challenges. The first one is how to detect very
early research topics that may not even be labelled. The second one is how to forecast
their impact with good accuracy. A specific set of sub-questions has been articulated
in order to describe the process through which the doctoral work plans to answer the
questions above.</p>
      <p>Q1 – Finding the data. Understanding which data to integrate and exploit for the
process is the first step. In particular, it is important to investigate the value of
nonscholarly data (e.g., tweets, blogs, micro-posts, slides) in supporting trend detection
and forecasting. As far as semantic technologies are concerned: how can research
elements be gathered and connected by means of semantic relations?</p>
      <p>Q2 – Detection of new emerging research topic. How is it possible to extract
patterns in the evolution of research areas in order to predict the emergences of new
ones? How can historical patterns be used to support the detection of future trends? Is
it possible to develop a general approach able to consider the peculiarities of different
fields (e.g., Computer Science, Business, Medicine and so on)? How emerging and
unnamed research areas can be labelled? How social media can contribute in the
detection of research trends?</p>
      <p>Q3 – Forecasting of research trends. Can the impact of a research topic be
measured just in terms of number of citations and publications? As soon as it has been
defined, how the impact of research areas can be forecasted? What kind of forecasting
approach should be adopted for research areas that do not yet exist? Which
contribution can be given from the social media?
5</p>
    </sec>
    <sec id="sec-5">
      <title>Hypotheses</title>
      <p>From a philosophical point of view, academic disciplines are specific branches of
knowledge which together form the unity of knowledge that has been produced by the
scientific endeavour. When two or more disciplines start to cooperate they share their
theories, concepts, methods and tools. The results of this cooperation may lead either
to the creation of a new interdisciplinary research area or simply to a contribution in
knowledge from one area to another. The basic hypothesis is that the creation of a
topic is thus anticipated by a number of dynamics involving a variety of research
entities, such as other topics, research communities, authors, venues and so on.
Therefore, recognizing these dynamics might enable a very early detection of emerging
topics.</p>
      <p>
        Scholarly data can be used to analyse a huge amount of research elements such as
papers, authors, affiliations, venues, topic and communities [
        <xref ref-type="bibr" rid="ref18">19</xref>
        ]. All these research
elements are inherently interconnected by relations that can be defined as either
explicit or implicit. Figure 1 shows, as an example, the six basic explicit connections
between the research elements according to our model.
      </p>
      <p>These explicit connections can be used to derive a number of second order
connections, e.g. a topic is also associated with publication venues through relevant papers
published in venues. These relationships can be analysed diachronically to derive the
dynamics that led to the emergence of a topic and to estimate how they affect its
future impact. For example, if two communities start to share research interests or
authors, this may lead to the fact that a common new topic is developing. In a nutshell,
the fundamental hypothesis at the basis of this PhD is that by exploiting the large
variety of scholarly data which are now available, as well as modelling their semantic
relationships, it will be possible to perform detection and forecasting of research
trends even in a relative small interval of time. In addition, since many researchers are
actively involved on social networks, I believe that analysing data from social media
can also provide an effective support for the detection of research dynamics.
6</p>
    </sec>
    <sec id="sec-6">
      <title>Approach</title>
      <p>The approach is structured according to the proposed research questions. Basically, it
is organised in four main steps.</p>
      <p>
        Data integration. In this first phase I plan to integrate a variety of heterogeneous
data sources, including both scholarly metadata and less traditional sources of
knowledge, such as tweets, blogs post, slides and so on. The output will be a
comprehensive knowledge base containing both the research entities from Figure 1 and
entities from social media (authors’ profiles, number of followers, analytics, etc.). I will
identify topics and communities by extending state of the art techniques. In particular,
I plan to treat topics semantically, by describing their relationships using the topic
networks produced by the Klink algorithm [
        <xref ref-type="bibr" rid="ref16">17</xref>
        ]. I am also planning to use the
approach for detecting topic-based research communities described in [
        <xref ref-type="bibr" rid="ref18">19</xref>
        ], since it
explicitly links communities and topics.
      </p>
      <p>The rich network of semantic relationship between the research elements will be
described by an ontology and it will be populated by semi-automatic statistical
methods. To build it, I plan to extend the topic network created by Klink with the research
entities discussed in section 5 and their relationships. The analysis of these
relationships and how they change in time will support the next steps of the approach.</p>
      <p>Exploration of the Research Dynamics. In this step, the dynamics involving
research elements correlated with the emergence of new topics will be investigated. To
do so, I plan to verify empirically a number of hypotheses about these dynamics. In
particular, I will analyse a number of topics which appear in the 2000-2010 interval
and verify if their emergence is correlated with a number of dynamics, such as the
raise of co-publications of related research areas, the increase of collaborations
between authors of related areas, shifts of interests or migration phenomena in related
communities, transfer of topics between related venues, and so on.</p>
      <p>The output of this analysis will be a collection of patterns of knowledge flows
associated with the creation of a new research area.</p>
      <p>Early topic detection. This step aims to exploit the previously defined patterns for
early research trend detection. To this end, I will build a number of distinct graphs, in
which nodes represent a kind of research entity (e.g., topics) and the links are one of
the elements of the dynamics, which were found in the previous phase – e.g., the
increase in the number of collaborations between authors from two distinct topics.
Highly connected sub-graphs, representing the area in which multiple entities exhibit
the identified dynamics could thus suggest that a new discipline is emerging. In order
to produce more robust evidence, I will use the semantic network of research entities
to confirm that the emergence of a new topic is supported by a number of different
‘traces’ and research entities. For example, if a set of topics suggests that a correlated
research area is emerging, the dynamics of the set of communities and venues related
to these topics will also be checked. The intuition is that, while the evidence coming
from a single dynamics or a single kind of entity could be biased or noisy, their
combination should yield a more accurate result. The result will be a number of sets of
linked entities, each one anticipating the emergence of a new topic. Different kinds of
combination of entities and metrics will be tested, aiming to find the best approach to
derive sets that are strongly correlated with the creation of new topics. At this stage,
another challenge will be the definition of a method for labelling future research
topics.</p>
      <p>
        Trend forecasting. Initially, I will investigate different techniques to estimate the
impact of a topic, taking in consideration both basic metrics, such as the number of
publications and citations, and more complex indexes. As mentioned before, in
contrast with current approaches, [
        <xref ref-type="bibr" rid="ref7 ref8">8,9</xref>
        ], I aim to develop a method which will be able to
work also on relatively short time series (6-18 months). In order to do so, I will take
advantage of a wide variety of features associated with a topic, representing both the
performances of related entities (e.g., the track record of significant authors) and the
previously discussed dynamics. Hence, I will conduct a comprehensive analysis of the
correlations between these features and the topic impact in the following years. For
example, I will analyse how the performance of related authors, communities,
workshops, hashtags, scientific opinion leaders, and so on, influence on the previously
defined impact metrics. It is hypothesised that such abundance and diversity of the
features will compensate for the small interval of time in which early topics will be
analysed. Moreover data from the social web and other real-time information, such as
the number of views and downloads on the publisher sites and open access
repositories, will offer a more granular timeline for the analysis of the topics, measured in
weeks, rather than in years.
      </p>
      <p>A set of different machine learning methods, such as Artificial Neural Networks,
Support Vector Machines and Deep Belief Networks, will exploit the extracted
features in order to forecast the performance of a topic.
7</p>
    </sec>
    <sec id="sec-7">
      <title>Evaluation plan</title>
      <p>I plan to conduct an iterative evaluation during the different phases of my work using
both quantitative and qualitative approaches.</p>
      <p>From a quantitative point of view, I will evaluate both the ability of the system to
identify novel topics and its accuracy to assess their impact in the following years.
The discussed approaches will be compared with current methods and the difference
between their performances will be measured via statistical tests. I will evaluate the
detection of emerging trends in terms of recall, precision and F-measure using
crossvalidation on historical data. Similarly, I will assess the agreement between the
estimated and the real impact of a research area.</p>
      <p>In the qualitative evaluation, the achieved results will be compared with experts’
opinions in order to measure its reliability. I will prepare a number of surveys for
domain experts with questions both about the past - such as the main topics recently
emerged in their area of expertise - and about the future - such as the research areas
which seem on the verge of being created and an estimation of their likely impact.
8</p>
    </sec>
    <sec id="sec-8">
      <title>Conclusions</title>
      <p>This paper presents the goal of my doctoral work, which is currently at an early stage
(month 6). As discussed, I intend to produce a new approach for detecting and
forecasting research trends, which is based on a semantic characterization of research
entities, on the statistical analysis of research dynamics and on the integration of
scholarly and social media data.</p>
      <p>Currently I am investigating a number of knowledge sources for selecting the ones
more apt to support my approach. At the same time I am using an initial dataset to test
the hypotheses about research dynamics discussed in section 6. The next step will be
the creation of an approach for extracting highly connected sub-graphs of entities
exhibiting dynamics associated with the emergence of new topics.</p>
    </sec>
    <sec id="sec-9">
      <title>Acknowledgements References</title>
      <p>I would like to acknowledge my advisors, Enrico Motta and Francesco Osborne, as
well as my sponsors, Springer-Verlag GMBH for supporting my research.
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