1. Introduction
The process of opinion formation in human society gains increased importance with the development of social networks, which have an important impact on political views and elections (see, e.g., [
1,
2]). The statistical properties of such social networks typically have a scale-free structure, as reviewed in [
3,
4]. Various voter models have been proposed and studied by different groups with the development of physical concepts and their applications to sociophysics [
3,
5,
6,
7,
8,
9,
10,
11].
Recently, we proposed the Ising Network Opinion Formation (INOF) model and analyzed its applications to Wikipedia networks for six language editions of 2017 [
12]. This model allows us to determine opinion polarization for all Wikipedia articles (or nodes) induced by two groups of nodes with fixed opposite opinions (red or blue, spin up or down). In this INOF model, the initial two groups of one or a few nodes have fixed opposite opinions represented by spin up (red color) or spin down (blue color). All other nodes initially have an undecided opinion (spin zero or white color). The formation of a steady-state opinion of each node emerges as a result of an asynchronous Monte Carlo process in which an opinion of a given node
i is determined by a majority vote of their friends presented by spins up or down or zero from all network nodes
j that have links to node
i. Such spin flips, induced by local majority votes, are performed for all nodes without repetitions in random order over all
N nodes. This procedure is repeated up to convergence to a steady state for a sufficiently long time
and corresponds to a particular random pathway realization for the order of spins to be flipped. Finally, an average over a high number of pathway realizations is found to obtain averages and distributions of the opinions for nodes or the whole network (see the next section for more technical details). A somewhat similar procedure is used in the studies of problems of associative memory (see, e.g., [
13,
14]), even if there are significant differences from the INOF model due to the absence of certain fixed nodes and other initially white nodes and the use of positive/negative transition elements between nodes, while all of them are positive for the INOF case considered here.
The mathematical and statistical properties of certain models of Ising spins on complex networks have been analyzed in [
15,
16]. However, these works studied very different aspects of such networks compared to those discussed in our work.
We also note that the INOF approach is generic and can be applied to various directed networks. In particular, it has also been applied to the analysis of fibrosis progression in the MetaCore network of protein–protein interactions [
17]. A similar approach, without white nodes, was used to study the competition of the dollar and possible BRICS currencies in the world trade network [
18].
In this work, we extend the studies of the INOF model [
12] to more recent Wikipedia networks collected either in October 2024 or on 20 March 2025 and to new specific initial groups with fixed opinions. For example, we analyze the competition between Apple Inc. vs. Microsoft, Donald Trump vs. Vladimir Putin, and others. Furthermore, the competition of three entries is also considered for several cases. Thus, we analyze the competition between three groups of Donald Trump, Vladimir Putin, and Xi Jinping and compare the results with the case of competition between three related countries: the USA, Russia, and China. We also show that the INOF approach allows us to analyze the interaction and influence of social concepts such as Liberalism, Communism, Nationalism. In this work, we consider two types of vote contributions (determined by two representations of
in (
1), see below), while only one of them was considered in [
12]. And finally, we also examine the effects of fluctuations appearing as a result of a certain effective temperature in the voting process.
Wikipedia networks have rather exceptional features compared to other networks: the meaning of their nodes is very clear, they represent all aspects of nature and human activity, and the presence of multiple language editions allows us to analyze various cultural views of humanity. A variety of academic research of Wikipedia with the analysis of different aspects of nature and society was reviewed in [
19,
20,
21,
22,
23]. Therefore, we hope that the INOF approach to Wikipedia Ising Networks (WINs) will find multiple and diverse applications.
The article is composed as follows:
Section 2 describes the INOF model and the used Wikipedia datasets,
Section 3 presents the results for the confrontation of opinions for two groups of entries,
Section 4 presents the results for the contest between the three groups,
Section 5 analyzes the effects of fluctuations induced by an effective temperature, and
Section 6 contains the discussion and conclusion. Finally,
Appendix A provides some additional figures and data.
We note that the preliminary results of this research have been presented at the contributed talk of the authors at Wiki Workshop 2025 on 22 May (the three-page abstract is available at [
23]).
2. Model Description and Datasets
In this work, we mostly use three very recent Wikipedia editions (English EN, Russian RU, Chinese ZH) collected on 20 March 2025 with the number of network nodes/articles being
and the number of links being
= 190,031,938, 44,188,839, 21,160,179 for EN, RU, and ZH, respectively. For certain cases, we also use the English (EN) and French (FR) Wikipedia network collected on 1 October 2024 and already used previously (see [
23] and Refs. therein) with
N = 6,891,535, 2,638,634 and
= 185,658,675, 76,118,849 for EN (2024) and FR (2024), respectively.
Wikipedia articles correspond to network nodes and citations from a given article
j to another article
i corresponding to a directed link with the adjacency matrix element
(and
in the absence of a link from
j to
i); multiple citations from
j to
i are considered as only one link. The above definition of the link directions of
corresponds to those used in our previous works, see, e.g., [
23] and Refs. therein, and we keep it here. Then, the matrix of Markov transitions is defined by
, where
is the number of outgoing links from node
j to any other node
i (such that
); for the case of dangling nodes without outgoing links (i.e., with
), we simply define
, implying the usual column sum normalization
for all
j. For later use, we also introduce the modified matrix
, which is identical to
for
and with
for dangling nodes.
Usually, in other typical types of network studies (see, e.g., [
23]), one introduces the Google matrix of the network defined as
, where alpha is the damping factor with the standard value
[
24,
25]. Here, the network nodes can be characterized by the PageRank vector, which is the eigenvector of the Google matrix
G [
24,
25] with the highest eigenvalue
, i.e.,
, and the damping factor
ensures that this vector is unique and can be computed efficiently. Its components
are positive and normalized to unity (
). The network nodes
i can be ordered by monotonically decreasing probabilities
, which provides the PageRank index
K with with highest probability at
and smallest at
. Some results for the PageRank vector and its index for recent Wikipedia editions of 2024 can be found at [
23] and Refs. therein. However, in this work, we do not use the Google matrix nor the PageRank and focus mostly on the modified matrix
and also the adjacency matrix
to define an asynchronous Monte Carlo process.
As in [
12], a few selected nodes (wiki-articles) have assigned fixed spin values
blue for Microsoft and
red for Apple Inc. These specific spin nodes always keep their polarization. All other nodes
i are initially assigned a white color (or spin
) and have no definite initial opinion. However, once they acquire a different color, red or blue (spin value
), during the asynchronous Monte Carlo process, they can flip only between
and cannot change back to the white opinion.
To define the asynchronous Monte Carlo process, we choose a random spin
i among the non-fixed set of spins and compute its influence score from ingoing links
j:
where the sum is over all nodes
j linking to node
i. Here,
is the element of the vote matrix, defined by one of two options:
(the adjacency matrix element, option OPA) or
(the modified Markov transition matrix element, option OPS). For the OPS option, the matrix
is used, in which columns corresponding to dangling nodes contain only zero elements, ensuring that these nodes do not contribute to
. We discuss both options, OPA and OPS, with a primary focus on the OPS case.
In Equation (
1),
if the spin of node
j is oriented up (red color),
if it is oriented down (blue color), or
if the node
j has no opinion (if it has still its initial white value). After the computation of
, the spin
of node
i is updated: it becomes
if
,
if
and remains unchanged if
. This operation is repeated for all non-fixed nodes
following a predetermined random order (shuffle), such that there is no repetition at this level and each spin is updated only once. Note that due to the possibility of
, it is possible that a node
i keeps its initial white value
. After the update of
, the modified value of
is used for the computation of
of subsequent values
.
One full pass of updating all non-fixed spins constitutes a single time step, . The procedure is then repeated for subsequent time steps using a new random shuffle for the update order at each step. We find that the final steady state is reached after steps with only a very small number of spin flips in the . There is a certain fraction of nodes that remain white for , which we attribute to their presence in isolated communities (about 12% for EN 2025, 15% for RU 2025, 30% for ZH 2025, and 10% for FR 2024). These nodes are not taken into account when determining the opinion polarization of other nodes and all statistical quantities such as averages, fractions, and histograms that are computed with respect to the set of non-white nodes. We point out that compared to the usual case of Wikipedia networks, the size of the configuration space of the INOF model is drastically increased to instead of N.
The physical interpretation of the OPA case corresponds to the situation where a node
j gives an unlimited number of votes to the nodes
i to which it has links, while for the OPS case, the node
j has only a limited vote capacity (since the total probability in column
j is normalized to unity). Therefore, these two options, OPA and OPS, describe two different possibilities for the voting process. We note that due to a misprint in [
12], the analysis was performed for the OPA case and not with the OPS one as it is declared in [
12].
Repeating this asynchronous Monte Carlo process, with the same initial condition and different random orders (or pathways) for the spin flip defined by rule (
1), we obtain various random realizations, leading to different final steady-state distributions in each case. Using these data, we perform an average of up to
pathway realizations (
for the case of FR 2024 to obtain a reduced statistical error for this case; see below) that provides an average opinion polarization
of a given spin (node, article). The further average of
over all (non-white) network nodes gives the global polarization
with a deviation of
for each article. This deviation
represents the opinion preference of a given article
i to red or blue entries as compared to the average global Wikipedia opinion
. The set of white nodes in the final steady-state distribution contains about 10–30% of the total number of nodes (30% only for ZH Wiki2025 and at most 15% for the other cases), and this set is extremely stable with respect to different pathway realizations and also with respect to the different choices of initial fixed nodes. These white nodes are not taken into account in the computation of
, and
is only computed for non-white nodes (those which have nearly always either red or blue values depending on the pathway realization). The voting process for the case of a competition between three groups of entries is an extension of this procedure, and its details will be explained later.
4. Results for Competition of Three Groups of Entries
It is possible to generalize the competition between two groups to a competition between three groups. A similar case for a competition of three currencies in world trade has been considered in [
18]. However, in [
18], there were no white nodes in the initial distribution of nodes, and the network size was very small, representing only about 200 countries (nodes).
As in the case of the competition of three currencies in [
18], the competition of three entries allows us to highlight more complex interactions between three selected entries compared to the case of only two entries.
For the case of three competing groups, we compute for a given node
i three scores
for three color values
C by the following:
Here,
if node
j has color
C; otherwise,
, and in the computation of
, only nodes
i with color
C contribute. Note that the white color counts as an effective fourth color which also has a score, but this fourth white score is not used in the spin update process of the Monte Carlo procedure. If among the three score values
(for the three non-white colors) there is a single clear maximum color
with
for
, the node
i will acquire the new color
. If there is no clear maximum, i.e., with at least two maximal identical values
(for
), the color of node
i will not be changed (it may also stay white if it was white before). Note that we consider the three group competitions only for the OPS case with
having fractional values. Therefore, the scenario of two equal maximal scores and a third strictly smaller score (
) is very rare. However, the scenario of having three identical values being zero
may happen quite regularly if all nodes
j with non-zero values of
in the sum (
2) still have their initial blank color.
After the color update of node
i, the Monte Carlo procedure is performed in the same way as for the above case (
1) of two colors: the small number of nodes of the three groups with initially fixed color are never updated (they have a “frozen”color), and the update procedure is performed in a random order for all other non-fixed nodes which have the white color as the initial condition. A full update run is repeated for up to
iterations at which nearly all node color values are stable and in a steady-state distribution. Finally, this procedure is repeated with the same initial condition but for
different random pathway realizations in the update order, which allows us to compute the averages and distributions of the obtained network color fractions.
As for the two group competitions, once a node switches from white to another color, it cannot go back to the initial white color, but even with this, there is still a significant fraction of nodes which stay (nearly) always white for all pathway realizations. The sets of of “white” nodes essentially only depend on the used Wikipedia edition (and not on the selected fixed color nodes for the competition) and these sets are also the same as for the two group competitions.
Formally, the competition of three colors is different from the Ising case of two colors with spins up or down, but we still keep notations INOF and WIN for the case of the three color competition since it appeared originally from the Ising-type spin relation (
1) with two colors. We note that in both procedures, the spin/color information propagates from the initial groups with frozen spin/color through the network and after
update iterations (per node), essentially all non-white nodes, have a stable spin/color value which no longer changes. However, the final spin/color value of each node depends strongly on the selected random pathway for the update order (see also
Figure 1).
We attribute to each of the three groups its own color being red, green, or blue (RGB) and compute for each (non-white) node the color polarization of color C as the fraction , where is the number of color C outcomes of node i in the pathway realizations. (Note that for the non-white nodes i, we typically have , while for the white nodes j, we have ).
From , we compute for its global network average (over non-white nodes), which is defined as , and we characterize the node preference for color C by the difference , which represents the color preference of node i in comparison to the global network color preference (both for color C).
For the three-entry analysis, where each of the three entries is mapped to an RGB color channel, we present two types of world map visualizations: Monochromatic Maps: Each map displays a single color channel (red, green, or blue). The color intensity is scaled by the value, ranging from zero to maximum saturation. Multicolor Maps: These maps use an RGB color triangle to represent the combination of the three entries. The triangle is constructed such that each vertex represents a pure color, corresponding to the maximum value of one component ( or ), while the other two are at their minima.
Concerning the statistical error of or , we mention that the theoretical error can be obtained in a similar way as for the case of two group competitions. Now, we use as the average (over the random pathway realizations) of , a quantity which has values of 0 or 1, such that . This allows for us to compute the variance from its average and gives the theoretical error of as for and (value of maximal theoretical error), which is similar to the two-color case. (The factor is a trivial effect of the formula for the two-color case.) We have also verified by the method of sample averages that the error of is typically reduced by the same factors of 2–3 as for the two-color case.
In the following, we present the results for the competition of the three groups in the next subsections for the three types of groups of political leaders, countries, and society political concepts.
4.1. Contest of Trump, Putin, and Xi Jinping
In
Figure 7, we present the world map of (monochromatic) color polarization of countries for
Donald Trump, Vladimir Putin, and Xi Jinping from the view of the three Wiki2025 editions: EN, RU, and ZH. The values of the global color polarization
of these three political leaders are given in the caption of
Figure 7 (of course
).
For EN, Putin has the highest color polarization, ahead of Trump and then Jinping. For Trump–Putin, their relative polarization remains approximately as in their own two-group contest presented in the previous section. It is interesting to note that in this case, there are more countries with in favor of Putin; also in this case, the maximal positive value is by a factor of three higher than for the case of Trump and by a factor of seven higher than for the case of Jinping.
For RU, the color polarization in favor of Putin extends over even more countries than expected. We attribute this to the fact that RU Wiki naturally gives a higher preference to the president of Russia.
The ZH edition naturally places Jinping at the highest global color polarization, followed by Trump and then Putin. The maximal polarization of countries is also by a factor of four higher compared to the cases of Trump and Putin, showing a high influence of Jinping on the world countries from the view point of the ZH edition.
Any color can be presented as a combination of three colors: red, green, and blue (RGB). Taking into account this property, we can make a summation of the three-color world map, shown in
Figure 7, for each country using its corresponding color average of
(for each edition) and as a result, obtain a color RGB world map of the countries. The result of this operation is presented in
Figure 8 for three editions: EN, RU, and ZH of Wiki 2025.
From the EN edition, we can see that the influence of Putin of course completely dominates in Russia and also propagates to former USSR republics (but it is not strong in the countries of Central Asia), and a few countries of East Europe, such as Romania, Hungary, and Serbia, and also with a smaller strength Turkey and Iran. The influence of Trump naturally dominates the USA and extends to Canada, Mexico, Latin America, the UK, Australia, New Zealand, Japan, and South Korea. The influence of Xi Jinping from China extends to India, Pakistan, and countries of South East Asia.
In the case of the RU edition, the influence of Putin propagates from Russia to former Soviet republics, Afghanistan, and, in a less strong way, to Turkey, Iran, and Poland. The influence of Trump is restricted to the USA, extending to Brazil, Argentina, and Mexico. The clear influence of Xi Jinping is well seen for Chad and Uruguay and is not well visible for other countries, which can be considered a significant exaggeration of the RU edition. There are many countries, with color being a mixture of red and blue (between the USA and Russia).
For the ZH edition, the influence of Xi Jinping propagates from China to Mongolia, Kazakhstan, and Kyrgyzstan, as the most obvious cases. The country colors for the influence of Trump and Putin are mixed and give no clear preferences.
In Appendix
Figure A2 and
Figure A3, we show the density, or frequency, of articles in the planes of color values
for the EN, RU, and ZH editions, which allows us to see in a better way the distribution of articles and their color polarizations (more technical details in the captions of these figures). Note that for the case of a pure two-group competition, these type of figures would give straight lines on the antidiagonal (from
to
), since, e.g.,
for a the pure
Trump–Putin competition. In Appendix
Figure A2, the data are indeed somewhat concentrated close to this antidiagonal, showing the that modifications due to the influence of the third group of
Jinping are rather modest for the editions of EN and RU.
5. Effects of Fluctuations at Effective Finite Temperature
For the competition of two groups with different opinions (red vs. blue), the relation (
1) for
determines the condition of spin updates with
if
,
if
and no spin change if
. Such a condition corresponds in the Monte Carlo process to the effective temperature
since it gives a firm choice for the updated spin. It is interesting to analyze how stable this procedure is in the presence of fluctuations produced by a finite effective temperature
T. A finite
T value physically corresponds to the presence of finite probabilities
(
) to obtain the new spin value
.
To model this situation, we write
as a difference of two positive quantities
(i.e., sum only over all
j with either
or
for the two cases + or −, respectively). This is similar to the color score
used in (
2) if we use only two colors for spins
. Then, the probabilities
are determined by the relations
where during a Monte Carlo step, the spin
i takes the value
with probability
. At
(
), we have
and
if
(
and
if
), which reproduces the previous spin update condition based on
or
. At high temperature
(
), we have
, such that the new spin value
is purely random with equal probabilities.
We mention that (
3) can be understood by introducing two virtual “energy levels”
such
(for each node
i, there is a different two-level system). In this case, the probabilities (
3) are just the usual probabilities of the levels
in the canonical ensemble at temperature
T for this two-level system:
.
The results for this finite temperature model of fluctuations are shown in
Figure 12 and
Figure 13.
Figure 12 shows that at
, the density distribution of the (network) fraction of red nodes
at maximal iteration time
is concentrated to the two regions
and
(similarly as
Figure 1, which corresponds to
). In contrast, at
, this density has a broad homogeneous distribution approximately in the range
, and at
, all density is located in a narrow range around
. Indeed, at such a high temperature, the probabilities to have spin up or down from (
3) are very close
, and hence we have approximately half of spins up and half down. The transition from a spin-polarized steady state at low temperatures to a non-polarized one takes place in the vicinity of a certain critical temperature
. Its value can be approximately determined by measuring the normalized number of spin flips or spin switches
at
maximal iteration time as a function of temperature
T. Up to now, this quantity (at
) is essentially zero since at
for a specific given pathway realization, the spins of individual nodes are mostly in stable steady state.
This dependence of
on temperature
T (and also on iteration time
) is shown in
Figure 13. This figure shows that the critical temperature is
, where we have a sharp increase in the number of flips (at
) and a rapid growth of the normalized switch number
. Thus, the obtained results of
Figure 12 and
Figure 13 show that the spin-polarized phase remains stable for the temperature range
, while above
, there is a melting of the polarized phase and we obtain a non-polarized liquid state at
, at which individual spins no longer have stable values with respect to iteration time, even at
. In particular, we see that for a
specific given random pathway realization at
or
, the spin values of individual nodes become stable in time (fluctuations discussed in the previous section are entirely due to the many
different random pathway realizations which produce
different steady states), while at
, there is no real spin-steady state (for a given pathway realization) and spins continue to be flipped even at
.
We argue that the main result of this effective temperature model (
3) is the fact that the polarized phase remains stable with respect to fluctuations at small or modest temperatures.
6. Discussion and Conclusions
In this work, we described the process of opinion formation appearing in Wikipedia Ising Networks (WINs) being based on an asynchronous Monte Carlo procedure. This INOF approach is determined by a simple natural rule that the opinion of a given node (article, user) in a network is determined by a majority opinion of other nodes connected to this given node. We discussed two possible voting procedures: the OPA case, where vote contributions are given by a sum over elements of the adjacency matrix
going to a selected given node
i, or the OPS case, when the weight of a vote is given by an element of the normalized matrix of Markov transitions
(see (
1)). Only the OPA case was considered in previous studies [
12]. We show that these two vote options give similar results, but specific vote polarizations may be different. We think that both vote options OPA and OPS can be suitable for the description of opinion formation on networks. Thus, for protein–protein interaction networks, we think that the OPS case, used for the MetaCore protein network in [
17], is more correct since the interaction capacity of a given protein is bounded by various chemical processes. The important new element of the INOF approach is the presence of white nodes with undefined opinion at the initial stage of the asynchronous Monte Carlo process. Our results show that the spin-polarized steady state remains stable with respect to small fluctuations at an effective temperature below a certain critical border, while above this border, there is a melting of this phase and a transition to a liquid non-polarized spin phase.
We also demonstrated that the situation with competition between two groups with fixed red/blue opinions can be generalized to the case of three competing groups with fixed opinions (red, green, blue), and that in this case, the generalized INOF approach leads to fair results for WIN.
For the EN, RY, and ZH editions of Wikipedia 2025, we compared opinions of different cultural views of these editions with respect to political leaders Donald Trump, Vladimir Putin, and Xi Jinping and determined their influence on 197 world counties. Surprisingly, Putin happens to produce a higher polarization influence in the EN edition. With the INOF approach, we also determined the influence of the USA, Russia, and China on other countries for these three editions. We also showed that other types of contests can be studied, like the competition between Liberalism, Communism, and Nationalism.
The described INOF approach is generic and can be applied to various directed networks. Thus, in [
17], this approach allowed for myocardial fibrosis progression to be described in the MetaCore network of protein–protein interactions. Also, a variation in this approach (without white nodes) determines the dominant features of trade currencies in the World Trade Network from the UN COMTRADE database [
18].
Of course, Wikipedia networks have important exceptional features compared to other networks: the meaning of their nodes is very clear, they enclose all aspects of nature and human activity, and the presence of multiple language editions allows us to analyze various cultural views of humanity. Thus, we hope that the INOF approach to Wikipedia Ising Networks will find diverse, interesting applications.