Text as data
Petr Ocelík and Lukáš Lehotský
Text analysis as approach
• Content analysis
• Supervised methods
• Unsupervised methods
• Discourse network analysis
• Grounded theory
• Qualitative discourse analysis
• …
Content analysis
• Question of manifest vs. latent content
• Berelson (1952) – objective, systematic, and quantitative
description of manifested content of communication
• Many other commit themselves to notion of content
being present in the message (Riffe, Lacy & Fico 1998;
Gerbner 1985; Shapiro & Markoff 1997)
• Other criticize this assumption (Krippendorff 2013;
Holsti 1969)
Design of CA research
Research
Question
Answers
Texts
Content Analysis
Krippendorff 2013, p. 36
Design of CA research
Unitizing Sampling
Recording/
Coding
ReducingInferringNarrating
Krippendorff 2013, p. 86
Unitizing
• Natural units
• Sentences
• Quasi-sentences
• Paragraphs
• Texts
• Constructed units
• N words
• N sentences
• ...
Sampling
• Sampling comparable to choosing a sample in
survey
• Random/non-random selection
• Selection
• Analysis of whole population will not yield additional
insights
• Practical considerations
Particular methods
Word frequencies
• Basic exploration of text corpus
• Bag-of-words assumption
• Assumption that words convey meaning
• Assumption that certain words describe particular
concept
Word frequencies
Term-document matrix
2003-
2004-cz
2004-
2005-pl
2005-
2006-hu
2006-
2007-sk
2007-
2008-cz Sum
agriculture 3 6 2 5 3 19
aim 4 2 7 12 6 31
area 11 8 8 28 26 81
base 1 2 2 2 5 12
border 5 9 9 3 3 29
central 2 3 6 3 5 19
cohesion 3 1 7 4 4 19
commission 2 7 3 2 4 18
common 10 9 17 8 17 61
community 2 2 3 3 6 16
concern 9 13 12 18 6 58
Wordclouds
Lehotsky, 2016
Lehotsky, 2016
Lehotsky, 2016
Term correlations
• Co-occurrence of terms within unit
• Bag-of-words assumption
• Assumption of semantic proximity of co-occurring
words
• Correlation coefficients such as Pearson’s
correlation coefficient
Coding
• Discovering concepts in text data
• Inductive (Glaser & Strauss, 1967)
• Generation of codebook from available textual data
• Open
• Axial
• Deductive (Lacewell, Volkens & Werner, 2014)
• Based on existing codebook
• CMP
Coding
• Best practices
• Two independent coders
• Method of agreement
• Measures of validity
• Krippendorff’s Alpha
• Misclassification (Mikhaylov, Laver & Benoit, 2011)
• Experimental approaches (Tosti-Kharas & Conley,
2016)
• Crowdsourcing academic tasks
• Countries of the Visegrad Group are facing similar challenges in the energy
sector, and are aware of the utmost importance of the issue of energy security.
• Energy policy concerns could be better dealt with on the basis of regional
cooperation, especially in diversifying the natural gas supply of the countries of
Central-, East- and South-East-Europe.
• Due to the lack of adequate interconnections and limited possibilities of reverse
flow among the countries of the region, the development of infrastructure of
transmission and storage of natural gas, crude oil and electricity is necessary in
order to eliminate barriers in the transmission of energy among the counties in
this region and to enable solidarity reaction to crises.
• Participants decided to further discuss the ways of improving the energy
security situation of our countries and to adopt the necessary measures which
may help weaken the impacts of any possible disruption of supply in the future.
• They expressed their support to strengthen cooperation in further integrating
their gas networks, including the Southern Corridor and the Nabucco Project as
well as the North-South transportation corridor through the region, the
planned Croatian and Polish Liquefied Natural Gas terminals and the NETS
project.
• Participants declared their willingness to provide support for the missing
interconnectors, including joint efforts for a higher allocation of EU financial
resources to all projects with the potential of increasing the energy security of
the region.
• Cooperation of energy companies of the region will also be further encouraged.
Lehmann et. al., 2017
Coding
2. MODERNIZACE ČESKÉ SPOLEČNOSTI NA
2.1. ZDRAVÁ EKONOMIKA – základ dlouhodobé prosperity NA
Globální prostředí NA
Globalizace zasahuje do všech oblastí našeho života a nelze jí uniknout. 107
Projevuje se například zvyšující se rychlostí kapitálových toků 408
nebo čím dál tím větším podílem levného spotřebního zboží z dovozu na trzích
vyspělejších zemí.
401
Globalizace je nejen příležitostí, ale také hrozbou. 107
Konkurenceschopnost asijských ekonomik se opírá o ekologický a sociální dumping. 503
Na mezinárodním poli budeme proto usilovat o postupné prosazování minimálních
sociálních a ekologických standardů
503
kombinovaných s promyšlenou (tzv. kvalifikovanou) ochranou evropského trhu. 406
Lehmann et. al., 2017
Keywords in Context (KWIC)
• Allows analysis of concept’s original proximate
surrounding (linguistic environment)
• extracted with the concept itself
• Corpus linguistics
• Useful for understanding concepts
• Initial coding might benefit
Keywords in Context (KWIC)
exchange of information about energy policy and coordination of
and coordination of the energy policy of V 4
sphere of new EU energy legislation, especially rule
of trans- European Energy Networks, concentrate on
with the operation of energy facility, impact of
the field of the energy sector, industry and
Energy continuation of meeting of
establishment of a common energy and gas market.
- operation in the energy sector in the usual
Osicka et. al., 2016
Dictionary-driven methods
• Words categorized in pre-existing dictionary
• Custom-made categories
• WordScores (Benoit & Laver, 2002; Laver, Benoit &
Garry, 2003)
• Sentiment analysis (SentiWords)
• Alternative to manual coding
• Strong assumptions
• Open for further analysis
Custom dictionary
• Natural gas – security context
• Security
• Supply
• Geopolitics
• Interrupt
• Cut
• Natural gas – market context
• Liquidity
• Market
• Trade
• Price
• Exchange
Sentiment analysis
• SentiWords (Guerini, Gatti & Turchi, 2013)
aristotelian_logic#n 0.15793
aristotelian#a 0
aristotelian#n 0
aristotle#n -0.01819
arithmetic_mean#n 0
happy#a 0.86753
sadist#n -0.72256
sadness#n -0.65005
thermonuclear_reactor#n 0
thermonuclear_warhead#n 0
Discourse Network Analysis
• Actors share beliefs and subscribe to particular
concepts (Leifeld & Haunss, 2012)
• Concepts may be captured through textual data
• Documents (manifestos, press releases…)
• Interviews
• Text coding
• Output as two-mode network data
• Actors
• Concepts (captured in codes)
Osicka et. al., 2016
Semantic networks
• Unsupervised method (Nerghes & Lee, 2015)
• Co-occurrence of words within a textual unit
• More co-occurrences indicate stronger relation
between words
• Clustering algorithms
• Clusters of words occurring together more frequently
than other
Lehotsky, 2016
Lehotsky, 2016
Lehotsky, 2017
Lehotsky, 2016
Topic modeling
• Topic model
• Bag-of-words assumption
• Latent semantic space
• Documents are mix of few topics
• Each word in document belongs to particular topic
• Approximation of distributions given corpus of data
• Latent Dirichlet Allocation (Blei, Ng & Jordan, 2003)
• Many other derived models - lifting some LDA
assumptions
• Wide range of issues
Blei, 2011
LDA topic model (9 topics)
elektrárna vláda firma voda težba mesto kraj dul clovek
zdroj ministr spolecnost krajina uhlí století práce uhlí zeme
uhlí volba CEZ území limit Ostrava region težba život
energie CSSD skupina obec obec zámek problém okd svet
elektrina ODS cena místo Jiretín památka program horník doba
plyn kraj uhlí mesto prolomení dum oblast spolecnost díte
cena návrh trh stavba obyvatel kostel rozvoj clovek cas
energetika vec prodej težba clovek Most nezamestnanost práce válka
zeme poslanec zisk projekt vláda hodina obcan zamestnanec praha
výroba zákon podíl most težar muzeum clovek tuna evropa
stát predseda výroba oblast Litvínov centrum místo karviná rodina
koncepce politika akcie peníze zásoba budova podpora mluvcí vetšina
prumysl KSCM NWR metr dum areál doba šachta místo
teplo Stát podnik jezero sdružení hrad stát reditel žena
Temelín premiér investice zóna CSA výstava pocet útlum muž
Ocelik & Lehotsky, 2017
Computer aids
• With graphical user interface
• Atlas.ti
• Nvivo
• MaxQDA
• WordStat
• Mallet (LDA)
• Programming languages
• R
• Python
• …