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    <article-meta>
      <title-group>
        <article-title>A Quick Intensive Course on Natural Language Processing applied to Literary Studies</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Borja Navarro-Colorado</string-name>
          <email>borja@dlsi.ua.es</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Department of Software and Computing Systems University of Alicante</institution>
        </aff>
      </contrib-group>
      <fpage>37</fpage>
      <lpage>42</lpage>
      <abstract>
        <p>This paper presents how Natural Language Processing is taught to students of a Master's Degree in Literary Studies. These students' background is solely humanistic, and they have no knowledge whatsoever of Natural Language Processing (NLP). The challenge is to introduce these students to the main aspects of NLP in a 20-hour course, and show them how they can apply these techniques to the analysis of literary texts. The course focuses on three main aspects: first, to get to know a new approach to literary text analysis based on the distant reading model; second, to develop a representative literary corpus and, finally, to apply basic NLP techniques to said corpus in order to extract relevant data. Among these techniques are word frequencies, Part of Speech tagging and distributional semantic models such as LDA Topic Modeling. Satisfaction surveys show that students are satisfied with the course.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1 Introduction</title>
      <p>Teaching Natural Language Processing to
Literature students is currently a great challenge.
Students come to the course with good skills for
closereading literary text analysis and a good
background in history of literature and even in literary
theory. However, they don’t have enough
technological or mathematical background in order to
understand how current Natural Language
Processing techniques work and how they can be applied
to the analysis of literary texts. Indeed, at the
beginning, they are unsure about the usefulness of
these resources for literary studies.</p>
      <p>
        In this paper I will present the objectives and
contents of a Master’s course (two credits) focused
on the application of computational techniques
(mainly Natural Language Processing) to literary
text analysis. The subject is framed in Moretti’s
distant reading model
        <xref ref-type="bibr" rid="ref14 ref15 ref5">(Moretti, 2007; Moretti, 2013;
Jockers, 2013)</xref>
        because I think that it is within this
approach that NLP techniques are really useful
for literary studies. Following a standard empirical
text-analysis process, the course is organized in two
main modules: the first one is devoted to corpus
design, compilation and annotation; and the second
one is devoted to the application of some specific
Natural Language Processing techniques such as,
among others, lexical frequencies analysis, part
of speech tagging, named-entities recognition or
distributional semantic analysis (LDA Topic
Modeling
        <xref ref-type="bibr" rid="ref2">(Blei et al., 2003)</xref>
        ). My procedure in class is
as follows: first I show my students how each of
these above-mentioned techniques work, and then
what can be expected from them when applied to
literary texts. This way students extract
empirical data from the corpus that they must interpret
according to their literary knowledge.
      </p>
      <p>Students usually pass the course without much
difficulty. Satisfaction surveys show that the course
is well received among students. In general they
assume the necessity of empirical data to complete
traditional literary analysis. However, only a few
students eventually apply some of these NLP
techniques in their final Master Thesis or PhD Thesis.</p>
      <p>In the next section I will present first the course
context and the student profile; then I will show the
main objectives of the course, how the content is
organized and how it is taught to students (theory
and practice); to conclude I will propose some ideas
for a Digital Humanities curriculum based on this
experience.</p>
    </sec>
    <sec id="sec-2">
      <title>Course context and student profile</title>
      <p>The course is called “Computer resources for
literary research”.1 It is a twenty-hour course included
1The course is taught in Spanish. The exact name is
“Recursos informa´ticos para la investigacio´n literaria”: http:
in the Master’s Degree on Literary Studies2 at the
University of Alicante (Spain). It is taught
face-toface in a computer lab classroom, where students
perform their tasks under the teacher’s supervision.
The only task that is done outside the computer
lab is the students’s final essay in which they must
apply the NLP techniques they have learned during
the course.</p>
      <p>The course is taught by a teacher whose
background is Spanish Language and Literature (B.A.)
with a PhD on Natural Language Processing. So
far it has been taught three times since 2014-2015
school year. The first year the course had an
attendance of 11 students, 12 students the second year
and finally 17 students this last year.</p>
      <p>The students who take this course are usually
young graduates in Literature. All of them share
a good background in humanities and history of
literature, and they use similar research methods
for the traditional analysis of literary texts. They
differ in the literary tradition that they have studied.
Most of them are graduates in English Literature
or Spanish (Castilian) Literature, but there are also
graduates in other literary traditions such as
Catalan, Arab or French Literature. Some of them have
background in Linguistics as well. In this context,
the course is focused mainly on the computational
analysis of Spanish (both Catalan and Castilian)
and English literary texts.</p>
      <p>The students’s knowledge about mathematics or
computers is poor; as far as mathematics is
concerned, their knowledge basically comes down to
what they learned in high school. As regarding
computers, they are digital natives and use
computers in their daily life. However, they have not
knowledge at all about Computer Science:
algorithms, programming, etc.</p>
      <p>On the other hand, these students are familiar
not only with the main concepts of Linguistics, but
also with the literary criticism models that apply
linguistic techniques to literary analysis (such as
Russian Formalism, Structuralism or New
Criticism). Therefore, they clearly understand the
linguistic aspects of Natural Language Processing
and its main problem (the linguistic ambiguity).
However, their lack of a thorough computational
knowledge makes it hard for them to understand
how NLP works, that is, the mathematical basis of
NLP. During the course not only do I explain how
//www.dlsi.ua.es/˜borja/riilua/
2https://maesl.ua.es/index.html
to use NLP tools, but also I try to clarify how they
work, that is, how these tools deal with linguistic
ambiguity.
3</p>
    </sec>
    <sec id="sec-3">
      <title>General objectives</title>
      <p>In only 20 teaching hours it is not possible to
introduce Python nor any other programming language
in the course. This limitation leaves most
Natural Language Processing tools out of the syllabus.
Moreover, I avoid focusing the course only on the
technical application of NLP tools. More than this,
students must understand the important
contribution of these tools to literary studies, mostly
because before they take this course, they do not see
why they must apply computational tools to the
analysis of literary texts. They have enough with
their (manual and close reading) methodological
skills and literary analysis models, so they do not
see the usefulness of computational analysis. If
I want to analyze the metrical aspects of Garc´ıa
Lorca’s “Little Viennese Waltz”, why do I need a
computer, when I can analyze properly all these
lines by hand? This question is related to the
usefulness of NLP for literary studies.</p>
      <p>Our first objective is to show that the application
of NLP techniques to literary text analysis makes
sense only if by using these techniques I can learn
something new about the literary phenomenon. The
application of NLP tools to emulate human analysis
makes no sense. On the contrary, it must be applied
where manual analysis cannot reach.</p>
      <p>
        In this regard, Moretti’s Distant Reading model
        <xref ref-type="bibr" rid="ref14 ref15 ref5">(Moretti, 2007; Moretti, 2013; Jockers, 2013)</xref>
        sets
up a framework where the computational analysis
of literary texts is not only useful but also
necessary. I am referring to the computational analysis
of large corpora in order to extract common
patterns and regularities from the texts and, in
general, implicit and unknown information that cannot
be extracted by means of a manual analysis. Of
course it is better to analyze manually the metrics
of Garc´ıa Lorca’s “Little Viennese Waltz”, but it
is not possible for a human being to analyze the
whole metrics of all Spanish Golden Age Poetry
(all the Spanish poetry composed during the 16th
and 17th centuries). In this case the usage of
computational analysis and NLP techniques is
mandatory, and it will probably show some regularities
about the period that traditional approaches are not
able to detect. Both approaches are, in the end,
complementary.
      </p>
      <p>The second objective of the course is to
formulate big questions. In order to apply the Distant
Reading model, students must first learn how to
formulate big literary questions, questions that could
be answered applying NLP techniques to large
literary corpus. At the beginning students pose small
questions as the base for the analysis of a single
novel or the work of a specific poet. I encourage
students to think of big literary questions: Not
questions about a specific author or a specific piece of
literary work, but questions about whole literary
periods or genres, for example.</p>
      <p>To develop this new point of view, I use the easy
but powerful Google Books n-gram viewer.3 It
allows the student to look for word and n-gram
frequencies on the Google Books collection and
display them in a timeline. With this tool students
practice how to think big. They formulate big
questions about literature or, in general, cultural aspects
and then look for data in the Google n-gram tool.
They then analyze the data provided by the tool and
try to answer the question. The kind of questions
formulated are based on Michel et al. (2011).</p>
      <p>
        Finally, the third main objective of the course
is to show that the application of these techniques
sometimes provides quantitative data that, rather
than answers, produce new research questions that
must be studied
        <xref ref-type="bibr" rid="ref14">(Moretti, 2007)</xref>
        .
      </p>
      <p>Once students accept these ideas they are ready
to learn about the technical aspects of NLP. Now
they are able to appreciate the usefulness of NLP
for literary studies and the course makes sense for
them.
4</p>
    </sec>
    <sec id="sec-4">
      <title>Content and lessons</title>
      <p>
        Content and syllabus are based on my own research
experience. This is why the content of the course
is structured following a standard empirical text
analysis. Given that the main objective of the
Master’s Degree is to prepare students for research in
literary studies, this structure fits well with student
expectations. In any case, content and lessons of
this course are not based on any specific previous
course. Besides my own experience, to set up the
course content I have taken into consideration
tutorials such as
        <xref ref-type="bibr" rid="ref9">(Manning, 2011)</xref>
        , handbooks such
as
        <xref ref-type="bibr" rid="ref18 ref6 ref8">(Jockers, 2014; Pustejovsky and Stubbs, 2013;
Jurafsky and Martin, 2008)</xref>
        , and some courses on
Corpus Linguistics such as
        <xref ref-type="bibr" rid="ref12">(McEnery, 2013)</xref>
        or on
Natural Language Processing such as (Jurafsky and
      </p>
      <sec id="sec-4-1">
        <title>Introduction. Objectives (2 hours).</title>
      </sec>
      <sec id="sec-4-2">
        <title>Module 1. Corpus compilation.</title>
      </sec>
      <sec id="sec-4-3">
        <title>1. Corpus design and compilation (2 hours). 2. Corpus annotation (4 hours).</title>
      </sec>
      <sec id="sec-4-4">
        <title>Module 2. Corpus analysis.</title>
      </sec>
      <sec id="sec-4-5">
        <title>3. Frequencies, n-grams and concordances</title>
        <p>(2 hours).
4. Regular Expressions (2 hours).
5. Natural Language Processing (4 hours).
6. Text mining (4 hours).</p>
        <p>The main idea of the first module is that only
with a representative literary corpus is it possible to
achieve reliable conclusions. The literary analysis
depends, eventually, on the quality of the corpus
and the annotation. In this module students learn
about basic aspects of Corpus Linguistics: how to
select representative texts according to a set of
objective criteria; how to find, download and clean
texts in order to obtain plain texts; how to store text
files; how to deal with textual codification
problems, etc. (Wynne, 2004; Bowker and Pearson,
2002; McEnery and Hardie, 2012)</p>
        <p>
          The second lesson of this module is an
introduction to manual corpus annotation. It includes such
topics as XML and TEI
          <xref ref-type="bibr" rid="ref20">(TEI Consortium, 2016)</xref>
          ,
the application of annotation guidelines so that
the resulting annotation is consistent and reliable,
or the evaluation of the annotation through
interannotators agreement
          <xref ref-type="bibr" rid="ref18">(Pustejovsky and Stubbs,
2013)</xref>
          .
        </p>
        <p>
          Along with this lesson I develop a simulation of
a corpus annotation process. As a main resource
I use the Corpus of Spanish Golden-Age Sonnets
(with metrical annotation)
          <xref ref-type="bibr" rid="ref16">(Navarro-Colorado et
al., 2016)</xref>
          .4 This corpus is suitable for this exercise
because it is freely available (including the
annotators’s guidelines), it follows the standard XML-TEI,
and it has been manually annotated with literary
information: the metrics of each line. This corpus
provides ample annotation practice, and eventually
the students can compare their own work with the
original corpus annotation.
        </p>
        <sec id="sec-4-5-1">
          <title>4https://github.com/bncolorado/</title>
          <p>CorpusSonetosSigloDeOro</p>
          <p>The second module is focused on the
computational analysis of a literary corpus. It is structured
in four lessons.</p>
          <p>
            The objective of the first lesson (number 3) is to
set up the basis for the computational treatment of
texts. Specifically, I show students how words are
transformed into numbers and what these numbers
represent. With AntConc tool
            <xref ref-type="bibr" rid="ref1">(Anthony, 2014)</xref>
            ,5
students perform several tasks such as: the
extraction of the most frequent tokens of the corpus
(including a stop-words filter), the extraction of
the most frequent n-grams, the estimation of the
type/token ratio, concordance analysis, or the
extraction of the most frequent lemmas. The main
conclusion of this lesson is that, when the corpus is
really large, it is difficult to extract generalizations
from it using these techniques
            <xref ref-type="bibr" rid="ref19">(Roe, 2012)</xref>
            .
          </p>
          <p>Lesson 4 is devoted to a gentle introduction to
regular expressions. The objective is to show
students how to formalize linguistic expressions.
Although it is not possible to go deeply into this
topics, students learn how to define regular expressions
that allow them to find words by stem or by rhyme,
or even conditional expressions (words that appear
before or after another word, etc.).</p>
          <p>The lesson devoted to Natural Language
Processing techniques (lesson 5) is focused on part of
speech (PoS) taggers, syntactic parsing and
namedentities (NE) recognition. In general, I show first
the main architecture of this kind of tools, then the
main problems (ambiguity) and finally the common
error rate.</p>
          <p>In the case of the part of speech tagger, for
example, I explain that each word-lemma is related to
all its possible parts of speech in a dictionary. This
way the PoS ambiguity problem is presented. Then
some standard solutions are explained, as the use of
a set of rules to specify the suitable part of speech
for each word in each context, or the application of
statistical information. Named-entities recognition
is explained in the same way. Syntactic parsing is
explained showing how Context Free Grammars
(CFG) and Probabilistic CFP work.</p>
          <p>In any case it is not our objective to explain
deeply the solutions to these problems (grammar
development, statistical learning, machine learning,
etc.). These concepts will be hard to follow for our
students. What is most important is that students
understand the computational problem. This way
they will apply these techniques knowing what they
can expect from them.</p>
          <p>
            The exercises in this lesson are carried out with
FreeLing
            <xref ref-type="bibr" rid="ref11 ref17 ref19 ref7">(Padro´ and Stanilovsky, 2012)</xref>
            . This tool
is appropriate for our course because it is
multilingual: It includes PoS tagger, NE recognition and
chunkers for Spanish, English, Catalan and other
languages. The drawback of FreeLing is that it
is hard to install and use. Among other things, it
has no graphical interface. To avoid installation
problems, instead of using FreeLing directly we
use a web application developed by Pompeu Fabra
University (UPF - Barcelona, Spain) called
ContaWords.6 Using this web application is very easy: It
allows students to upload several text files that are
analyzed by FreeLing on a remote server. Results
are returned in a spreadsheet format. To obtain the
data in a spreadsheet is a must: Students can
create graphics and analyze the data extracted directly
from their corpus.
          </p>
          <p>The final section of this module is devoted to
computational semantics (lesson 6). Among all the
different computational semantic models that have
been proposed (lexical semantics, first-order logic,
events and semantic roles, etc.), our course is solely
focused on distributional models of semantics. I
explain only this model because it allows an
efficient computational processing of large corpora,
and because it can only be used with computers.</p>
          <p>
            Two main theoretical concepts are explained in
this lesson: first the idea lying behind distributional
semantics that the meaning of a word depends on
its contexts and words that occur in similar contexts
have similar meaning
            <xref ref-type="bibr" rid="ref4">(Harris, 1968)</xref>
            , and second
how computers deal with word contexts by means
of vectors and matrices
            <xref ref-type="bibr" rid="ref21">(Turney and Pantel, 2010)</xref>
            .
How it is possible to know the semantic similarity
between two words in the distributional framework
is shown following Widdows (2004).
          </p>
          <p>
            In order to show students how distributional
models of semantics (and, in general, text mining
techniques) are able to extract generalizations and
regularities from large corpora, I explain LDA Topic
Modeling
            <xref ref-type="bibr" rid="ref2">(Blei et al., 2003)</xref>
            . I describe how it
works and how it can cluster words with similar
(distributional) meaning in the same topic.
          </p>
          <p>
            Once students understand how LDA works, it is
applied to a literary corpus using MALLET
            <xref ref-type="bibr" rid="ref10">(McCallum, 2002)</xref>
            . Students must extract a set of topic
5http://www.laurenceanthony.net/
software/antconc/
          </p>
        </sec>
        <sec id="sec-4-5-2">
          <title>6http://contawords.iula.upf.edu/</title>
          <p>executions
models and analyze them. They check if topic
models are coherent, and if the words grouping in each
topic could be justified by means of literary criteria.
As I said before, I encourage students to formulate
questions (as, for example “why words A and B
are in the same topic?”) and try to answer them
according to their background in literature.
5</p>
        </sec>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>Evaluation</title>
      <p>With the exception of MALLET, which is the most
complex tool used in the course, students do not
have much difficulty using the technology and
completing the exercises in the syllabus, and eventually
they all pass the course.</p>
      <p>In order to monitor courses, the University of
Alicante distributes a survey in order to know the
degree of satisfaction of the students with the course
taken. This course was marked with 9 points out
of 10, showing that students are really satisfied
with the course. For us, these data show that the
approach used to teaching NLP in literary
studies is appropriate. However, only a few students
apply some of these techniques in their final
Master Thesis or PhD Thesis. Perhaps students need
more time to assimilate all these new techniques
and apply them to their daily research in literature.
6</p>
    </sec>
    <sec id="sec-6">
      <title>Conclusions</title>
      <p>In this paper I have presented the key points of our
approach to teaching NLP to students of literature.
I try to open the students’s mind with these main
ideas:
1. The use of NLP techniques in literary
studies makes sense when they are applied where
manual analysis cannot reach (the analysis of
large literary corpora).
2. This literary analysis approach requires a wide
scope -students must extend their point of
view and learn how to formulate big research
questions.
3. The application of these techniques
sometimes provides data that, rather than giving
answers produces new research questions.</p>
      <p>The course is structured following a standard
empirical text analysis: compiling, first, a
representative literary corpus, and then analyzing it with
NLP techniques (frequencies, part os speech
tagging, LDA Topic Modeling, etc.). As the course has
only 20 hours, I do not go deeply into the technical
details of NLP. I first explain how each technique
works and then students apply them to the corpus
with easy-to-use tools.</p>
    </sec>
    <sec id="sec-7">
      <title>Acknowledgments</title>
      <p>I would like to thank the anonymous reviewers for
their helpful suggestions and comments. Thanks
also to my students for their feedback that helps
me to improve the course.</p>
      <p>Paper partially supported by the BBVA
Foundation: grants for research groups 2016, project
“Distant Reading Approach to Golden-Age Spanish
Sonnets”</p>
      <p>Antconc
software].</p>
      <p>Tokyo, Japan:</p>
    </sec>
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