=Paper= {{Paper |id=Vol-3286/04_paper |storemode=property |title=Detecting the Semantic Shift of Values in Cultural Heritage Document Collections (short paper) |pdfUrl=https://ceur-ws.org/Vol-3286/04_paper.pdf |volume=Vol-3286 |authors=Alfio Ferrara,Stefano Montanelli,Martin Ruskov |dblpUrl=https://dblp.org/rec/conf/aiia/FerraraMR22 }} ==Detecting the Semantic Shift of Values in Cultural Heritage Document Collections (short paper)== https://ceur-ws.org/Vol-3286/04_paper.pdf
Detecting the Semantic Shift of Values in Cultural
Heritage Document Collections (short paper)
Alfio Ferrara1 , Stefano Montanelli1 and Martin Ruskov1
1
 UniversitΓ  degli Studi di Milano
Department of Computer Science
Via Celoria, 18 - 20133 Milano, Italy


                                         Abstract
                                         The paper presents the main features and goals of the EU H2020 VAST (Values Across Space and Time)
                                         project about the transformation of moral values across space and time, with particular emphasis on the
                                         core European Values that represent the essential pillars of the EU society. In particular, we discuss the
                                         preliminary results obtained by analysing a selected collection of historical documents by employing
                                         machine learning techniques. The aim is to classify document annotations and their relationships with
                                         values to discover possible shifts in the value meaning when different temporal contexts are considered.

                                         Keywords
                                         semantic shift detection, natural language processing, computational humanities




1. Introduction
The rapid development and diffusion of artificial intelligence techniques and data science
approaches enable research in the field of humanities and social sciences to become more
and more computational. Various studies are being appearing to exploit artificial intelligence
techniques for heritage representation and processing, like for example the analysis of literary
texts and historical documents, or the extraction of knowledge from spontaneous contributions
provided by people involved in artistic/cultural experiences such as museum visits and theatrical
plays [1, 2]. As a consequence, we are witnessing a shift from digital humanities to the so-called
computational humanities research, where the role of artificial intelligence, data science and
cutting edge digital technologies is fundamental to achieve research advances and results [3].
   In this paper, we present the ongoing experience of VAST (Values Across Space and Time),
an EU H2020 project providing a concrete example of computational humanities and, more
specifically, computational history research (https://www.vast-project.eu/). VAST aims to study
the transformation of moral values across space and time, with particular emphasis on the

1st Italian Workshop on Artificial Intelligence for Cultural Heritage (AI4CH22), co-located with the 21st International
Conference of the Italian Association for Artificial Intelligence (AIxIA 2022). 28 November 2022, Udine, Italy.
$ alfio.ferrara@unimi.it (A. Ferrara); stefano.montanelli@unimi.it (S. Montanelli); martin.ruskov@unimi.it
(M. Ruskov)
Β€ https://islab.di.unimi.it/team/alfio.ferrara@unimi.it (A. Ferrara);
https://islab.di.unimi.it/team/stefano.montanelli@unimi.it (S. Montanelli);
https://islab.di.unimi.it/team/martin.ruskov@unimi.it (M. Ruskov)
 0000-0002-4991-4984 (A. Ferrara); 0000-0002-6594-6644 (S. Montanelli); 0000-0001-5337-0636 (M. Ruskov)
                                       Β© 2022 Copyright for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0).
    CEUR
    Workshop
    Proceedings
                  http://ceur-ws.org
                  ISSN 1613-0073
                                       CEUR Workshop Proceedings (CEUR-WS.org)



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Alfio Ferrara et al.                                 Cultural Heritage (AI4CH) -Workshop Proceedings


core European Values, such as freedom, democracy, equality, rule of law, tolerance, dialogue,
and dignity [4]. Across time, from antiquity to modernity, a value represents a message that is
communicated through different mediums (e.g., text, visual art, drama, oral narration) and this
message can change when the context and the society where citizens live change. As a first goal,
VAST aims at representing values and associated messages as they are extracted from documents
of the past, such as for example literature texts. Beyond this, the VAST project will study how
moral values are communicated and perceived today, by collecting, digitising, and analysing
narratives and experiences of both communicators of moral values, like for example artists,
directors, culture and creative industry institutions, museum curators, storytellers, educators,
and the respective audiences, like spectators, museum visitors, students, and pupils.
   In the following, we focus on the VAST approach developed in the project to extract knowledge
from a selected collection of annotated documents. In particular, we explored the use of Natural
Language Processing (NLP) techniques (i.e., word2vec) to classify the document annotations and
their relationships with values to discover possible shifts in the value meaning when different
temporal contexts are considered, namely the so-called project pilots. As a contribution, we
provide some preliminary results on the VAST dataset to show the possible employment of
machine learning techniques to automatically recognise semantic shift of values within a given
document corpus.
   The paper is organized as follows. Section 2 provides an overview of the VAST project. In
Section 3, the VAST approach to semantic shift detection is presented. Preliminary results on
the analysis of semantic shift on values are discussed in Section 4. Related work and concluding
remarks are finally given in Section 5 and 6, respectively.


2. The VAST project overview
The purpose of VAST is to enhance the metadata of existing digital resources according to moral
values in order to track values in space and time and to study how these values are appropriated
in different cultural and societal contexts. The project is structured in three pilots, each of them
concerned to a specific historical period and characterized by a general context, a narrative type,
communication mediums and tangible and intangible assets [5]. The selection of three specific
historical periods allow us to navigate the vastness of history making more comprehensible our
study on the transformation of values. The space, as well as the time, is a core aspect of the
project: VAST mainly focuses on Western Europe.
   Pilot A: Ancient Greek Drama is related to values in ancient Greek tragedies and how they
are perceived by contemporary theatrical plays and general audiences. The goal is to analyze
how the values of the antiquity, that are recognized to be discussed in specific tragedies (e.g.,
Lysistrata, Comedy, 411 BC), are revisited in the present through modern artistic reproductions,
such as acting, music, and voice.
   Pilot B: Scientific Revolution Texts is related to values in texts of 17th century about natural
philosophy and how they are perceived by experts in science museums and museum visitors
like students and pupils. The texts considered in the project are mostly about imaginary travel
stories or fictional communities of ideal perfection in which the new intellectual achievements
were embedded in an imaginary narrative context (e.g., The Man in the Moone, Francis Godwin,



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Alfio Ferrara et al.                                             Cultural Heritage (AI4CH) -Workshop Proceedings


1638).
   Pilot C: European Folktales is related to values in folktales throughout the History of
Europe and how they are perceived by storytelling experts in fairytale museums and museum
visitors. Though fictitious, folktales are important simulations of the reality. Moreover, the
variability of tales makes them the ideal case study for cross-cultural comparisons on social
dynamics, including cooperation, competition, or decision making. The pilot is mainly focused
on archetypical stories (e.g., the Grimms’ Fairy Tales, 1812) and it includes texts from several
European countries (i.e., Portugal, Italy, Slovenia, Greece, Cyprus).


3. Semantic shift detection in VAST
The VAST approach to semantic shift of values is based on the use of word embedding techniques
to analyse and compare the value interpretations across the three project pilots. The use of
embeddings for semantic shift detection is getting more and more attention in the literature, by
leveraging the idea that semantically-related words are close to each other in a given embedding
space (see Section 5). In the literature, both context-free and contextualised embedding models
are proposed. In VAST, we exploit a context-free solution (i.e., Word2Vec), mainly due to the
limited extension of the considered document collection and to the availability of the documents
as a static corpus without the incremental insertion of new texts throughout time. In our
approach, a fine-tuning step is also performed to obtain pilot-specific models that are exploited
to enforce the effective comparison of value descriptions across the pilots.
   The VAST approach relies on a collection π’Ÿ = {𝐷𝐴 βˆͺ𝐷𝐡 βˆͺ𝐷𝐢 } composed of documents from
Pilot A, Pilot B, and Pilot C, respectively. We work only with consolidated English translations
of the original texts1 . The approach is articulated as follows (see Figure 1):

        VAST Document Collection                  VAST
                                                  Labels

         𝐷𝐴          𝐷𝐡         𝐷𝐢             Document              Model       𝑀0        Fine       𝑀𝑖       Label
                                               Annotation           Training              Tuning              Analysis
       Pilot A     Pilot B    Pilot C


Figure 1: The VAST approach to semantic shift of values


   Document annotation. This stage has the goal to associate the VAST documents in π’Ÿ with
labels that are descriptive of the values to recognise. A reference vocabulary has been defined
in the project and it is composed of around 100 labels about values. A team of scholar experts
is involved in the project to perform the annotation task. Each scholar is focused on a single
pilot of her/his expertise and she/he has to read the full set of pilot documents and to highlight
specific text snippets by associating the vocabulary labels that she/he considers appropriate

1
    The full list of documents in the dataset is available at https://contents.islab.di.unimi.it/vastdocs/vast_collection_
    fulltext.zip.



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Alfio Ferrara et al.                                         Cultural Heritage (AI4CH) -Workshop Proceedings


according to an annotation methodology defined in the project. These expert annotations are
included in the documents by inserting the labels used for annotation at the beginning and at
the end of the annotated snippets.
   Model training. This stage has the goal to train a word embedding model for representing
the annotated documents of the collection π’Ÿ [6]. The document collection is submitted to a
lemmatisation process and the word2vec algorithm is then employed [7]. As a result, a word2vec
model 𝑀0 is created for the collection π’Ÿ about all the three project pilots.
   Fine-tuning. This stage has the goal to update the model 𝑀0 into three models, each one
specific of a pilot and related documents. The goal is to obtain pilot models that are able to
capture the language peculiarities of the pilot time-periods. The result of fine-tuning over 𝑀0
is the creation of three pilot models 𝑀𝐴 , 𝑀𝐡 , and 𝑀𝐢 , each one trained by considering the
documents in 𝐷𝐴 , 𝐷𝐡 , and 𝐷𝐢 , respectively.
   Label analysis. This stage has the goal to exploit the pilot models and to support the cross-pilot
comparison of vectors related to target words, namely the values considered in VAST (e.g., justice).
Two different analysis based on graph similarity and embedding clustering will be presented in
Section 4.

Example. A summary view of pilot documents considered in VAST is provided in Table 1. As
an example of document annotation, consider the Brothers Grimm’s version of the Snow-White
fairy-tale and the following excerpt (pilot C): β€œshe realized that the huntsman had deceived her,
and that Snow-White was still alive”. A VAST expert of pilot C annotated this snippet with the
label deceptiveness vs honesty belonging to the VAST vocabulary.

Table 1
Summary view of VAST pilot documents
                       Pilot                                Docs   Words    Annotations
                       Pilot A: Greek Tragedy                 20   57 578          1788
                       Pilot B: Scientific Revolution         18   74 291          2098
                       Pilot C: Fairy-Tales                   12   55 623          1692




4. Analysis of semantic shift of values
By relying on the embedding models 𝑀𝐴 , 𝑀𝐡 , and 𝑀𝐢 , in the following, we describe two
different analysis where we compare the labels about the VAST values in the three project pilots
with the aim to observe possible changes/shifts.

4.1. Similarity Graph of pilot labels
In this analysis, we build a similarity graph for each pilot where the nodes represent the labels of
the VAST vocabularies and the edges denote similarities between pairs of nodes according to the
cosine similarity calculated by considering the word embeddings (a threshold πœƒ = 0.45 is applied
in our experiments to filter poorly-relevant similarity values). The similarity graphs allow to



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Alfio Ferrara et al.                                                                                         Cultural Heritage (AI4CH) -Workshop Proceedings


immediately analyse the shift of a value in the three pilots by observing how the neighborhood
changes in the corresponding graphs for a given label. An example of the resulting similarity
graphs over the pilots is shown in Figure 2 where 10 labels per pilot are considered.

                    tradition        progress                                             tradition         progress                                             tradition     progress
  gender               vs                                               gender               vs                                               gender                vs
 equality          innovation                           validation     equality          innovation                          validation      equality           innovation                      validation




     speculation                                    freedom                speculation                                   freedom                 speculation                                freedom
                           PILOT A                                                               PILOT B                                                                PILOT C
         vs                                             vs                     vs                                            vs                      vs                                         vs
     observation                                     slavery               observation                                    slavery                observation                                 slavery




evidence            clarity                             research      evidence            clarity                            research      evidence              clarity                        research
   vs                 vs           demonstrable         freedom          vs                 vs            demonstrable       freedom          vs                   vs        demonstrable       freedom
authority          ambiguity          truth                           authority          ambiguity           truth                         authority            ambiguity       truth




Figure 2: An example of similarity graph over a subset of labels in the VAST vocabulary


   In the example, we note that the similarity between validation and clarity vs ambiguity persists in
all the three pilots, meaning that such a relationship emerges in the whole dataset. Furthermore,
we note that the similarity between gender equality and freedom vs slavery emerges only in pilot
B about the Scientific Revolution texts. On the contrary, the similarity between progress and
demonstrable truth via speculation vs observation are valid only in Pilots A and C.

4.2. Clustering of pilot labels
In this analysis, we build clusters of similar labels by relying on the similarity links over the
labels calculated in the three pilots. In our experiment, the clique percolation method is exploited
over the pilot-oriented similarity graphs and three sets of cluster labels are defined (i.e., one
cluster-set per pilot). The similarity clusters allow to analyse the shift of a value in the three
pilots by observing the overlaps and the differences on the obtained clusters in relation to a
given label/value. An example of the resulting clusters over the pilots is shown in Figure 3
where we focus on the free thinking label/value.


                                                                                                PILOT B
                                                               equality, objectivity, good vs evil, human rights, transparency vs secrecy

                                                                                                evidence,                                 freedom vs slavery,
                                                  research freedom,                       integrity, ingenuity,                             gender equality,
                                                       dialogue                         validation, free thinking,
                                PILOT A                                                                                                         justice        PILOT C
                                                                               demonstrable truth, clarity vs ambiguity,
                               democracy,                                                                                                                  honesty, kindness,
                                                                          tradition vs innovation, speculation vs observation
                               science for                                                                                                                   gratitude vs
                               public good                                                                                                                    ingratitude
                                                                                           knowledge, progress,
                                                                                                 reason



Figure 3: An example of cluster overlap across the three pilots for the label free thinking


   The intersection for the three pilots shows the shared theme of the clusters: centred around e.g.
validation, free thinking, and integrity. In Pilot A, the label democracy emerges and it is coherent




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Alfio Ferrara et al.                                 Cultural Heritage (AI4CH) -Workshop Proceedings


with the historical period of this pilot (i.e., the Ancient Greece), whereas freedom vs slavery and
gender equality are not as prominent as in the other pilots. In Pilot B, the labels objectivity and
human rights emerge and this is coherent with the Scientific Revolution period. Finally, honesty
and kindness emerge in Pilot C, as typical moral values of the considered folktales.


5. Related work
The proposed VAST approach to shift detection of value meanings is closely related to the
more general issue of semantic shift detection. In this context, a recent review of approaches is
provided in [6] where the authors distinguish between word- and sense-level changes. Typically,
word-level approaches focus on detecting changes on a single word meaning that is assumed
to be the dominant one, whereas sense-based approaches focus on recognizing changes by
considering also the so-called minor meanings. The use of a single, shared embedding, like the
one used in VAST, is framed as a word-level approach and it allows to compare the embeddings
of different pilots (i.e., sub-corpora) since they are aligned within the same vector space. In [8],
a solution based on word2vec and Cosine Similarity is proposed. As a difference with our VAST
approach, they consider the time in which the documents are added to the corpus, so they split
the corpus in sub-corpora and they train the model on the first sub-corpus by fine-tuning it on
the following periods, resulting in a model for each period.
   The use of word embedding implies that the document analysis is focused and constrained
by the considered corpus used for training. Thus, the results of semantic shift detection only
represents a snapshot that depends on the actual semantics of the given vocabulary/corpus [9].
As a consequence, shifts might appear for β€œsomewhat different from what a historical linguist
would expect to see” [10]. This requires the capability to interpret the recognised shifts and
to classify the word changes according to possible categories like i) words of strongly context-
dependent meaning, ii) words frequently used in a very specific context in a particular time bin,
and iii) words undergoing syntactic changes, not semantic ones.
   As a final remark, solutions for semantic shift detection based on contextual word embedding
are also being appearing in the literature (e.g., [11, 12]).


6. Concluding remarks
In this paper, we presented the preliminary results of the VAST project about the shift of values
across three different project pilots based on a selected document collection. The obtained
results provide interesting suggestions for possible improvements and further investigations.
   Ongoing and future work are about i) the enrichment of the document collection with
nowadays textual sources collected from non-expert users involved in VAST activities (e.g.,
museum visitors, theatrical actors/curators), and ii) the creation of an ontological knowledge
base about the project pilots derived from the similarity graphs and clusters obtained in our
experiment.




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Alfio Ferrara et al.                               Cultural Heritage (AI4CH) -Workshop Proceedings


Acknowledgments
     This project has received funding from the European Union’s Horizon 2020 research and
     ⋆ ⋆ ⋆
 ⋆           ⋆
 ⋆           ⋆
 ⋆           ⋆
     ⋆ ⋆ ⋆




innovation programme under grant agreement No 101004949. This document reflects only the
author’s view and the European Commission is not responsible for any use that may be made
of the information it contains.


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Alfio Ferrara et al.                             Cultural Heritage (AI4CH) -Workshop Proceedings


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