Wiki Workshop (10th edition) – May 11, 2023

Controversies over Historical Revisionism in Wikipedia
Taehee Kim
University of Oldenburg

David Garcia
University of Konstanz

Abstract
This study investigates the development of historical revisionism on Wikipedia. The edit history of Wikipedia pages allows us to trace thedynamics of individuals and coordinated groups
surrounding controversial topics. This projectfocuses on Japan, where there has been a recent
increase in right-wing discourse and dissemination of different interpretations of historicalevents.
Keywords: Edit wars, historical revisionism, Japanese
Wikipedia, right-wing populism, disinformation

Introduction
Historical revisionism refers to the reinterpretation or
rewriting of historical events, often with the goal of promoting a particular political or ideological agenda. In
particular, right-wing populism often employs historical revisionism to promote national identity and patriotic pride to mobilize support and achieve their political
agenda (Faber, 2023). In recent years, as right-wing
populism has gained momentum (Hann, 2019), historicalrevisionism driven by right-wing populism has become
increasingly visible in many countries (Berkofsky, 2022;
Laczó, 2022). As a result, the rise of right-wing populism
can impact the social acceptance of certain historical perspectives and make it easier for individuals or groups whobelieve in those perspectives to spread their reinterpreted
versions of history. However, our understanding of these
phenomena is still limited.
This study aims to investigate the recent development
concerning historical revisionism using Wikipedia data.
Wikipedia is an ideal platform to capture the developmentof interest since anyone can edit almost any Wikipedia
article. Although content on Wikipedia must be written from a neutral point of view (NPOV), edits can bedriven by the editor’s ideological alignment – reflecting
ideas of society members – especially if a topic is ideologically controversial (Leshnick, 2022; Greenstein etal., 2021). Moreover, given the high number of readersof Wikipedia and its central role in the online information ecosystem (Vincent et al., 2018), it is reasonable
to assume that some individuals and groups might be

Pablo AragónWikimedia Foundationinterested in disseminating their version of “facts” on
Wikipedia articles. As all edits are recorded, we cantrace the dynamics of individuals and coordinated groups
surrounding controversial topics. This exploratory study
aims to address the following questions:
1. What types of historical topics are most susceptible
to historical revisionism?
2. What are the common factors for the historical topics
that are subject to revisionism?
3. Are there groups of editors who are seeking to disseminate revisionist narratives?
This project focuses specifically on Japan, where politics has taken a rightward turn in recent decades, accompanied by the rise of radical right-wingers (Higuchi,2018). Previous studies pointed out that right-wingers
in Japan have disseminated revisionists claim, and somehistorical pages on the Japanese Wikipedia were edited ina way that reflects radical right-wing ideas (Sato, 2021).
Revisionist claims often center events that occurred WorldWar II, with a particular focus on war crimes and related
topics (Yamaguchi, 2022; Berkofsky, 2022).Therefore, in
our analysis, we focus on articles related to Japanese war
crimes and events surrounding World War II.

Methods
Data collection We collected a total of 74,010 articles
on Japanese history from four Wikipedia categories andone portal page (Table 1). The portal page introduced
a wide range of articles related to WWII and Japaneseperceptions toward the events. Given that these articles
are curated by a group of editors who have knowledge inthe topic, it is likely that they are at the center of the topic
and thus potentially contentious.
To find the historical topics which are susceptible torevisionism, we focus on the level of controversy of historical articles. It is likely that when revisionism is introduced, particularly when it is motivated by politicalor ideological agendas, it leads to “edit wars”. Based on
this premise, we expect that articles with a higher level ofcontroversy are more likely to be subjected to revisionism. To determine which article categories are potentially© Copyright held by the owner/author(s), published under Creative Commons CC BY 4.0 LicenseWiki Workshop (10th edition) – May 11, 2023
Source#articles

Category:History of Japan †Category:Japanese war crimes *Category:Japan’s postwar settlement *Category:Pacific war *Portal:Historical perceptions and postwar settlement

70,886
1,942
1,890
4,519
225

Total number (after deduplication)

74,010

articles (Table 3), particularly those related to right-wingideology (Figure 3). These findings suggest the possible presence of groups of editors seeking to disseminate
revisionist narratives.

References
Table 1: Collected article titles by source category. ∗:All articles including its sub-categories are collected. †:All articles under the main category and three further
levels of sub-categories are collected.
more susceptible to revisionism, we compare the levelsof controversy across different category of articles. Asfor controversiality, we rely on the 𝑀 measurement thatfocuses on editor’s mutual reverts as an indicator of controversy (Sumi et al., 2011).
After measuring the level of controversy of the articles,
we select highly controversial articles for further investigation (the target articles). To address the second question, we first examine the common factors that contributeto high levels of controversy. To achieve this, we analyze
the talk pages and the most contentious texts of the target
articles. We also explore the relationship between thesecontroversial factors and revisionist arguments made byradical-right wingers. Additionally, we track the target
articles’ development in terms of controversy level andeditor contributions.
To address the third question, we analyze the contribution patterns of editors to the target articles. Our assumption is that editors who are seeking to disseminate
revisionist ideas will contribute to a wide range of controversial topics, regardless of dissimilarity of the articles’
topics, and are more likely to be involved in ”edit wars”
than other editors. Based on this assumption, we compare the average number of articles contributed by editors
who have been involved in edit wars, specifically those
who were mutually reverted in any articles from our datacollection, with other editors for the target articles. Our
expectation is that if there are groups of editors interested in disseminating revisionist ideas, these mutuallyreverted editors will show a significantly higher level ofparticipation in the target articles.

Findings
Articles related to WWII exhibited significantly greater
controversy than general historical articles (Figure 1).
Among the top 20 most controversial articles, eleven werelargely related to Japanese war crimes and right-wing ideology (Table 2). Over time, the number of contributing
editors and the level of controversy increased (Figure 2).
Furthermore, editors involved in edit wars were more
likely to contribute to a higher number of controversial[Berkofsky2022] Axel Berkofsky. 2022. The History andPresent of Japanese Nationalism: Was Alive Yesterday, Is Alive Today. In Jan Záhořı́k and Antonio M.
Morone, editors, Histories of Nationalism beyond Europe: Myths, Elitism and Transnational Connections,
Palgrave Studies in Political History, pages 147–166.
Springer International Publishing, Cham.
[Faber2023] Sebastiaan Faber. 2023. Populism and theCollective Past: Revisionism or Memory Activism? In
The Routledge Handbook of Memory Activism. Routledge. Num Pages: 7.
[Greenstein et al.2021] Shane Greenstein, Grace Gu, andFeng Zhu. 2021. Ideology and Composition Amongan Online Crowd: Evidence from Wikipedians. Management Science, 67(5):3067–3086, May.
[Hann2019] Chris Hann. 2019. Anthropology andpopulism. Anthropology Today, 35(1):1–2. eprint:
https://onlinelibrary.wiley.com/doi/pdf/10.1111/14678322.12479.
[Higuchi2018] Naoto Higuchi. 2018. The Radical Rightin Japan. In Jens Rydgren, editor, The Oxford Handbook of the Radical Right. Oxford University Press.
[Laczó2022] Ferenc Laczó. 2022. Creeping Right-Wing
Hegemony and Its Contestations: On Public History inContemporary Hungary. International Public History,
5(1):43–52, June. Publisher: De Gruyter Oldenbourg.
[Leshnick2022] Anat Leshnick. 2022. Deletion discussions on Hebrew Wikipedia: Negotiating global
and local ideologies. New Media & Society, page146144482110678, January.
[Sato2021] Yumiko Sato. 2021. Non-English Editions ofWikipedia Have a Misinformation Problem. Slate.
[Sumi et al.2011] Robert Sumi, Taha Yasseri, Andr´sRung, Andr´s Kornai, and J´nos Kertesz. 2011. EditWars in Wikipedia. In 2011 IEEE Third International
Conference on Privacy, Security, Risk and Trust and2011 IEEE Third International Conference on SocialComputing, pages 724–727, October.
[Vincent et al.2018] Nicholas Vincent, Isaac Johnson,and Brent Hecht. 2018. Examining wikipedia with abroader lens: Quantifying the value of wikipedia’s relationships with other large-scale online communities.
In 2018 Conference on Human Factors in Computing
Systems, CHI ’18, page 1–13, New York, NY, USA.
Association for Computing Machinery.
[Yamaguchi2022] Tomomi Yamaguchi. 2022. Ramseyer,the Japanese Right-wing and the “History Wars”. Journal of International Women’s Studies, 24(9), December.

© Copyright held by the owner/author(s), published under Creative Commons CC BY 4.0 LicenseWiki Workshop (10th edition) – May 11, 2023

Figure 1: The average M score by category. Verticallines indicate 95%-confidence interval. A: Historical articles; B: Pacific war; C: Japan’s postwar settlement; D:Japanese war crimes; E: Historical recognision and postwar settlement (Portal)

M scoreTitle in English

17941
9308
4796
3944
3136
2730
2700
2349
2040
1846
1760

A. Nanjing Massacre ∗†B. Shintaro Ishihara
C. Mizuho Fukushima
D. Special Privileges of the Zainichi †E. Nanjing Massacre denial ∗†F. Second Sino-Japanese War ∗†G. Comfort women ∗†H. Mitsubishi A6M Zero
I. Battle of Okinawa ∗†J. War Guilt Information Program †K. Senkaku Islands †Figure 2: Development of the target Articles. For article
titles, see Table 2. M: M scores; #User: number ofcontributed editors; Reverts: a line indicates the presenceof reverts in the corresponding months, with line width
representing the number of reverts.

Table 2: The most controversial articles related to Japan’s
historical recognition and postwar settlement. ∗ and †indicate articles related to war crimes and right-wing ideology, respectively.

Mutually reverted users
OthersNmeant-value

368
6665

1.64
1.17

6.056
–

Table 3: T-test result: Comparing the number of contributed articles for the target articles between mutually
reverted editors and others.

Figure 3: Similarity network of the target articles basedon the overlap of editors who have contributed to them.
Nodes indicate articles, and edges indicate similarity(Yule’s Q > 0.3). The left graph shows the network
considering all editors, while the right graph only considers mutually reverted editors. All edges are significant
at the 5% level based on chi-squared test. Thicker lines
indicate higher Yule’s Q values.

© Copyright held by the owner/author(s), published under Creative Commons CC BY 4.0 License