Social network theory focuses on the role of social relationships in transmitting information, channeling personal or media influence, and enabling attitudinal or behavioral change. Since the 1960s, social network theory has significantly expanded the horizon of media effects research, with increasing application of network analytic methods in various empirical contexts. The two-step flow of communication hypothesis, the theory of weak ties, and the theory of diffusion of innovations are three major theoretical approaches that integrate network concepts in understanding the flow of mediated information and its effects.

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Social Network Theory

WENLIN LIU, ANUPREET SIDHU, AMANDA M. BEACOM,

and THOMAS W. VALENTE

University of Southern California, USA

Research history and key concepts

A diverse array of research traditions has shaped the current state of social network

theory. As Scott (1991) summarizes, there are three lines of research that contributed

to the theory's early development: the sociometric analysis tradition, which relies on

graph theory methods from mathematics; the interpersonal relations tradition, which

focuses on the formation of cliques among a group of individuals; and an anthropol-

ogy tradition that explores the structure of community relations in less developed

societies.

ese research traditions did not evolve into a coherent theoretical framework until

the 1960s. A number of sociologists signicantly advanced the social network approach

by synthesizing previous theoretical traditions and extending them to understand both

formal and informal social relations. For example, the sociometric view of social net-

works was elaborated, emphasizing structural properties, such as the relative location

of individual nodes in the network. Researchers during this time also advanced social

networktechniquesbyproposingblock modeling and multidimensional scaling .Block

modeling considers the particular position of a node in a social network. is method

enables researchers to identify nodes that have similar network positions, or what is

called structurally equivalent nodes. e scaling technique, on the other hand, allows

researchers to convert social relationships into sociometric distance ,therebymapping

these relationships in a social space (Wasserman & Faust, 1994).

ree key network concepts that have organized research on network eects are

centrality, cohesion, and structural equivalence. Freeman (1979) proposed three dis-

tinct measures to indicate structural centrality: degree, closeness, and betweenness.

is seminal paper aorded a nuanced understanding of centrality, and it established

a process through which new network measures were developed to have a raw form,

a normalized form, and a network-level form. Freeman's (1979) paper also motivated

subsequent research to assess how dierent forms of network centrality interact with the

ow of information dierently. For example, Borgatti's simulation study (2005) identi-

ed a typology of ow processes, and he showed that the values of dierent central posi-

tions depend on the characteristics of the process (e.g., gossip diusion versus goods

delivery).

Network cohesion measures the degree of interconnections among a group of nodes.

is measure has long been useful to detect subgroups or cliques within the larger

e International Encyclopedia of Media Eects.

Patrick Rössler (Editor-in-Chief), Cynthia A. Honer, and Liesbet van Zoonen (Associate Editors).

© 2017 John Wiley & Sons, Inc. Published 2017 by John Wiley & Sons, Inc.

DOI: 10.1002/9781118783764.wbieme0092

2SOCIAL NETWORK THEORY

social network (Burt, 1987). In the context of media eects research, network cohesion

serves as an important structural feature that moderates the inuence of interpersonal

networks. Friedkin's (1993) longitudinal study, among others, found that personal inu-

ence grows stronger within more cohesive social networks than less cohesive ones.

Finally, structural equivalence indicates two or more network positions that share a

similar pattern of connections with the rest of the network. Actors that occupy struc-

turally equivalent positions oen have similar characteristics, such as social status or

other individual traits. Because equivalent nodes are connected to a similar set of actors,

they are more likely to receive similar information or social inuence. In understanding

the process of diusion, Burt's (1987) study found that innovations were more likely to

ow via structural equivalence than direct ties, suggesting equivalence inuence may

be a stronger predictor of behavioral adoption than cohesive inuence. Burt (1999)

further elaborated on these mechanisms to explain the role of opinion leaders in the

media eects context. He argued that there were two dierent network mechanisms at

play: a two-step ow process that consisted of opinion leaders spreading information to

the group, and a contagion process via structural equivalence that generated adoption

behaviors within the group.

e years since the 1990s have witnessed extensive applications of key network

concepts in diverse research contexts, and the eld has also constantly been updated

with more rened network measures and analytic tools. In the arena of media

eects research, the fundamental question is: How do social networks, including the

quality and quantity of relational ties, the structural position of individual actors in

anetwork,andtheoverallnetworkproperties(e.g.,itsdensity,centralization,and

modularity) impact the ow of media messages and their eects on the audience?

ese eects include public opinion formation, marketing, uses and gratications of

media consumption, and behavior change due to prosocial campaigns.

Although communication research did not substantially shape the initial develop-

ment of social network theory, there is an emerging trend of cross-pollination between

social network theory and media eects research. In large part, this cross-pollination

stems from the emergence of computer-mediated communication, which aords

explicit social networks as well as the modes of communication that bind them. e

following sections review three theoretical approaches that best represent the inuence

of social network theory.

Two-step flow of communication hypothesis

e two-step ow of communication hypothesis was rst proposed by Lazarsfeld,

Berelson and Gaudet in the book e People's Choice (1944). In their study of voting

decisions, they found personal inuence, which was largely derived from people's

social contacts and friendship networks, signicantly aected voting decisions. And

this eect was even more pronounced among people who were less committed to their

existing beliefs or who changed their minds during the course of a campaign. e

hypothesis is called two-step because the mass media initially inuence opinion leaders,

individuals who are perceived as inuential, who in turn inuence their social contacts.

SOCIAL NETWORK THEORY 3

Building on its initial formulation, Katz (1957) reviewed a number of corroborating

studies on this hypothesis and further elaborated on three important aspects of it.

First, the magnitude of personal inuence could be greater than that of mass media,

as rst identied in the 1940s voting study. Similar ndings also emerged from

subsequent cases, such as the Decatur Study, which examined individuals' fashion

decision making (Katz & Lazarsfeld, 1955). Second, in terms of the ow of personal

inuence, opinion leaders are not always concentrated at certain social strata, nor

does personal inuence always ow from a higher social stratum to a lower one. On

the contrary, studies have observed many cases of local leadership or issue-specic

leadership. at is, leaders dier for dierent groups of people and leaders lead in

some domains but not others. Finally, personal inuence does not necessarily work in

isolation from mass media. e voting study revealed that opinion leaders tended to

be those who were more exposed to the mass media. And, depending on the specic

context, personal inuence can either reinforce or attenuate the eect of traditional

mass media.

Central to the two-step ow of communication process is the concept of opinion

leaders, a group of individuals inuential in specic domains. Numerous studies have

attempted to identify the key characteristics associated with being inuential along

three lines (Katz, 1957): who one is , the individual characteristics of the opinion leaders,

such as personality traits, charisma, or demographic and socioeconomic backgrounds;

what one knows, the characteristics pertaining to individuals' competence, such as

their knowledge, expertise, or ability to provide information or guidance on particular

issues; and whom one knows , the characteristics related to an individual's structural

position in a network. In other words, individuals may become opinion leaders

not only because they possess certain attributes but also because they occupy the

right network positions that enable them to eectively spread information and exert

personal inuence. Centrality measures have been particularly useful for identifying

leaders based on their network position.

As discussed, social network theory has proposed three types of network centrality

measures to identify the advantageous position that opinion leaders usually occupy:

degree, betweenness, and closeness (Freeman, 1979). Degree centrality measures the

number of links to and from an individual in a network. Individuals with high degree

centrality are more likely to become opinion leaders because more social ties can mean

greater opportunities to receive as well as disseminate information (see Figure 1, black

node). Betweenness centrality measures the frequency at which an individual node

lies on the shortest path connecting other nodes in the network. Individuals high in

betweenness centrality are more likely to serve as a bridge in the network—dened as a

node that connects otherwise unconnected network clusters. Just like gatekeepers in a

network, if individuals high in betweenness centrality oppose the dissemination of an

idea, this piece of information may not be able to ow to other areas of the network. In

Figure 1, the light gray node occupies this critical position. Finally, closeness central-

ity measures the average distance between an individual node and all other nodes in

the network. Individuals with higher closeness centrality need relatively fewer steps to

reach all other individuals in the network and thus can potentially move information

faster. e ability to eectively reach other contacts in one's network makes individuals

4SOCIAL NETWORK THEORY

Opinion leaders with high

degree centrality

Opinion leaders with high

closeness centrality

Opinion leaders with high

betweenness centrality

Figure 1 Network illustration of opinion leaders with high degree centrality, closeness central-

ity, and betweenness centrality. Source: Adapted from Everett's kite, in Brandes and Hildenbrand,

2014.

with high closeness centrality inuential. In Figure 1, the dark gray nodes have high

closeness centrality.

As one of the most applied theories in media eects research, the two-step ow of

communication hypothesis has been rigorously tested in various empirical settings.

e research on public opinion formation and agenda-setting, for instance, has

studied how inuential individuals, such as early recognizers of social issues, may

mediate the public and the media agendas by identifying emerging issues in the

media, diusing them among public audiences, and ultimately aecting the media

agenda (Brosius & Weimann, 1996). Research on health interventions has examined

thedualinuencesofinterpersonalnetworksandmassmedia.InValenteandSaba's

(1998) study of a reproductive health communication campaign, they found both

the mass media campaign and personal networks were associated with individuals'

contraceptive adoption, but the impact of mass media was stronger for low threshold

individuals, those whose personal networks were composed of few contraceptive

users, than high threshold individuals, those whose networks contained a majority

of users.

Although the two-step ow hypothesis has been validated in numerous studies,

scholarship since the 1980s has pointed out that media inuence may take multiple,

recursive steps, and the overall process is more complex thana singular, one-directional

ow. With the rapid change in today's media and communication environment, some

scholars also argue that the role of opinion leaders is becoming less pivotal. Bennett

and Manheim (2006), among others, have proposed that the traditional two-step ow

of media messages has gradually transformed into a one-step ow process, where

SOCIAL NETWORK THEORY 5

mass media are becoming more fragmented and niche media increasingly engage

in narrowcasting . Under this changed landscape, media messages may directly reach

their audience and opinion leaders thus would play a less signicant role than was

previously theorized.

Thetheoryofweakties

e theory of weak ties, articulated in Granovetter's (1973) seminal piece "e Strength

of Weak Ties," concerns the role of weak social ties in diusing ideas and informa-

tion. In his labor-market study, Granovetter observed that people more oen found jobs

through their weak social ties, as opposed to relying on their family or close friends. He

measured tie strength through the frequency of contact, asking respondents how oen

theysaweachcontactaroundthetimetheyacquiredthepieceofjobinformation.

In addition to contact frequency, studies have proposed a combination of factors to

indicate the strength of social ties, such as the duration of interaction, the amount of

eort individuals invest in a relationship, the extent to which the social ties provide

reciprocal utility (e.g., social support), and the level of intimacy exchanged in a relation-

ship. Based on these criteria, weak ties are generally dened as social relations requiring

little investment, and they are composed mostly of acquaintances or other loosely con-

nected actors, as opposed to kin or close friends.

Why are weak ties more likely to channel novel information than strong ties? To

explain the underlying mechanism of Granovetter's ndings, it is necessary to return

to the network concept of bridging, mentioned previously in the denition of between-

ness centrality. Bridging ties are social connections that link two otherwise unconnected

network clusters. In other words, bridging ties provide the only path between two dis-

connected clusters, such as Cluster A and Cluster B in Figure 2. Granovetter found weak

ties were more likely to be bridging ties, because weak ties' peripheral position made

them better able to reach outside information than strong ties. In Figure 2, imagine each

network cluster represents a circle of close friends, as all the nodes in each cluster are

connected to each other. In such highly interconnected circles, each person is likely to

Cluster A

Bridging tie

Cluster B

Figure 2 Bridging ties.

6SOCIAL NETWORK THEORY

receive a similar set of information. e bridging tie (sitting between the two clusters),

on the other hand, becomes the only opportunity for any nodes in Cluster A to access

novel information from Cluster B.

Although strong ties oen emerge from the center of a network, which gives

them greater capacity to diuse information and exert social inuence, Granovetter's

thesis highlights the bridging function of weak ties and their ability to spread novel,

nonredundant information. e strength of weak ties, therefore, is not about the

numberofconnections.Rather,itliesinweakties'abilitytoreachabroader,and

potentially more heterogeneous, set of information sources. In the process of job

hunting, for example, the utility of strong ties diminishes, because they provide similar

and potentially redundant information to individuals.

Granovetter'sndingshaveledtoaseriesofreplicationstudies,suchasinthecon-

text of general information seeking, organizational knowledge sharing, the diusion

of innovations, community building, and many more. In the area of media eects,

studies have explored the role of weak discussion ties in promoting civic engagement.

For example, de Zúñiga and Valenzuela (2011) examined the association between

strong versus weak ties and individuals' online and oine civic engagement. Among

factors such as discussion frequency and discussion network size, they found the

frequency of weak-tie discussion was the strongest predictor of individuals' civic

behaviors.

e emergence of new media and social networking sites has created an increase in

online weak ties. Indeed, new media provide novel platforms through which individuals

can connect with geographically distant others, and functions such as "add friends,"

"follow the post," "mention," and "retweet" have been theorized as forms of weak social

ties. Some research has found evidence of online, mediated weak ties in maintaining

individuals' bridging social capital, such as Ellison, Steineld, and Lampe's (2007) study

on college students' Facebook friends networks, whereas other scholars have argued

that online connections may breed slacktivism , as they fail to nurture meaningful civic

participation. e rise of new media platforms thus urges scholars to reconsider the

denition, conceptual boundary, and new typologies of weak ties. It also encourages

new research to examine the role of mediated weak ties in diusing information and

exerting social inuence.

Diffusion of innovations

e diusion of innovations occurs between individuals or organizations in a social

system.econnectionpatternbetweentheactorswhoinitiate,relay,andadoptinno-

vations can be viewed as a social network, where network connections may take the

form of friendship, advice, communication, or social support. e diusion process is

essentiallyanetworkedprocess.Asinnovationstravelthroughaninterconnectedweb

of social connections, the structure and characteristics of this network can determine

how widely and how soon the innovations get adopted (Valente, 1995).

InseveraleditionsofthebookDiusion of Innovations , Rogers (2010) formally intro-

duced the model for diusion and dened it as "the process in which an innovation

SOCIAL NETWORK THEORY 7

is communicated through certain channels over time among the members of a social

system" (p. 5). Rice (2011) dened the process of diusion in the context of media eects

"as the process through which an innovation (an idea, product, technology, process, or

service) spreads (more or less rapidly, in more or less the same form) through mass

and digital media, and interpersonal and network communication, over time, through

a social system, with a wide variety of consequences (positive and negative)" (p. 1).

e groundbreaking study in the eld of diusion was conducted by Ryan and

Gross in 1943 while they were investigating the diusion of hybrid corn seeds among

farmers in Iowa (see Valente, 1995). e early network approach of diusion studies

looked at how opinion leader status, indicated by the number of times an individual

was nominated as a network partner, was correlated with the time of adoption. Later

there emerged a more structural approach, and this approach shied the focus to

examine how the overall network pattern inuenced the adoption of innovations,

such as network density, the presence of weak ties (Granovetter, 1973) or structurally

equivalent positions (Burt, 1987), and so forth. Valente (1995) proposed a social net-

work threshold model, and this model is particularly characterized by its system-level

emphasis.

A large body of diusion studies has focused on identifying the factors and forces

that lead to the adoption of innovations among members of a certain population. ese

studies also aim to understand why some individuals or organizations adopt the inno-

vation sooner while others take more time to accept the same idea or practice. Current

scholarship has identied four main elements of the diusion model (Rogers, 2010;

Valente, 1995): the rate of adoption, which can be inuenced by the perceived char-

acteristics of the innovation and can be measured by mathematical models (Valente,

1995); the rate of adoption over time, which yields a cumulative S-shaped pattern; the

various stages during the adoption process, which can be further classied as knowl-

edge, persuasion, decision, implementation, and conrmation; and the modication of

the innovation.

In general, the adoption process entails learning about a new product, getting more

information about it, making a decision to adopt it or not, experimenting with it, and

eventually conrming the use of the product. e pace of diusion can be determined

by certain characteristics of the innovation, which include its: relative advantage, com-

patibility, complexity, trialability, observability, cost, and radicalness. Less radical, less

complex, and less expensive innovations, and innovations perceived as more advanta-

geous, compatible, trialable, and observable, spread more rapidly.

e ve adoption stages—knowledge, persuasion, decision, implementation, and

conrmation—have long been useful for understanding media eects and behavioral

change. Additional theories have further developed the adoption stages to evaluate

media campaign eects. For example, the hierarchy of eects model proposed 12

steps leading to behavioral change, and it estimated that individuals usually proceed

from one step to the next at a rate of 80% (Valente, 1995). e transtheoretical model

proposed specic cognitive stages of change—precontemplation, contemplation,

preparation, action, and maintenance—for quitting a behavior such as smoking

(Prochaska, DiClemente, & Norcross, 1992). It should be noted that a homogenous

model usually cannot capture the varying diusion processes in dierent contexts.

8SOCIAL NETWORK THEORY

Networkmodelshavebeendevelopedtomodelsocialinuenceprocesseswith

network weight matrices, such as relational, positional, and centrality measures, and

the weights based on social distance.

Diusion research peaked in the early 1960s, and it has been rekindled with the

rapid emergence of newer and more advanced network models and technology. e

application of diusion theory spans a wide array of disciplines, such as marketing,

economics, mathematics, sociology, anthropology, and epidemiology, among many

others. In the area of media eects research, the main premise of the theory is that

innovations enter into communities from external sources such as mass media or tech-

nological advancements, and then they spread via social networks and interpersonal

communication.

Mass media play a critical role in initiating diusion among opinion leaders and low

threshold adopters, as these individuals are more likely to rely solely on media infor-

mation to adopt an innovation (Figure 3). For opinion leaders or early adopters, their

initial decision of adoption may be independent of their social network ties. rough

processes such as the two-step ow, opinion leaders then spread the innovation to their

adjacent social network partners. At this stage, the early majority and late majority

may seek additional validating information to reduce uncertainty regarding the inno-

vation, from both traditional mass media and online media platforms such as Facebook

and Google. Toole, Cha, and González (2012) studied the spatiotemporal adoption of

Twitter, a microblogging web application, while also considering the interplay between

media and word of mouth. Media inuences at later stages of adoption increased the

Twitter user base twofold to fourfold. A study on news diusion across various social

media platforms analyzed over 386 million Web documents over a 1-month period in

2011. It found that, depending on issue domains, dierent types of media had varying

Cluster A

Bridging tie

Mass media

Cluster B

1

3

3

3

3

3

4

4

4

1

2

2

2

2

2

2

2

2

Figure 3 Two-step ow. 1: early adopter; 2: early majority; 3: late majority; 4: laggards.

SOCIAL NETWORK THEORY 9

degreesofinuence.Specically,socialnetworkingsitesandblogsweremostinuential

in politics and culture, news media in the arts and economics, social media in controver-

sial topics such as protests, and single social platforms in entertainment (Kim, Newth, &

Christen, 2013). erefore, media can inuence one's perception of innovations as well

as one's adoption behaviors.

Key contributions and future directions

Social network theory and methods oer a distinct perspective on and set of tools

with which to understand media eects, enabling consideration of how micro- and

macrosocial structures mediate and moderate media eects. e theories of two-step

ow and diusion of innovations examine the paths by which mediated messages travel

through social networks, and the concepts of opinion leadership and tie strength oer

insights into critical variables that aect this ow. While each of the theories discussed

here was developed in the twentieth century during the golden age of mass media tech-

nologies, their theoretical contributions endure as scholars continue to test and rene

them in an era of social media and rapid evolution in media technologies. ree direc-

tions for current and future research are highlighted below.

First, new media technologies such as social networking sites, microblogging tools,

and online recommendation systems oer intriguing opportunities for further appli-

cation and extension of social network theory in the study of media eects. Current

research in this area falls into two broad categories. One category investigates whether

and how network-based media eects theories such as diusion and the strength of

weak ties operate dierently in dierent forms of social, as opposed to mass, media.

Forexample,researchsuggeststhatsomeofthetraditionalsocialnetworkmeasuresof

opinion leadership discussed above may not be the best indicators of social inuence

on Twitter (Gruzd & Wellman, 2014). A second category of research capitalizes on the

large amount of and novel types of data available through social media to rigorously

test network-based media eects theories in ways not previously possible. For example,

largecorpusesofdigitaltracedatathatavoidpotentialself-reportbiasesofsurveydata

can be used to create randomized controlled experiments of the diusion of consumer

and political behavior on Facebook.

Second, media eects researchers have begun to extend social network theory and

methods beyond classic social contagion processes to engage in what Ognyanova and

Monge (2013) describe as a "relational reinterpretation" of numerous mass communi-

cation phenomena. Hyperlink networks, for example, in which the nodes are websites

and the ties are the hyperlinks that connect them, may be analyzed to trace the dif-

fusion of content between mainstream media and blogs, or to determine the extent to

which prominent mainstream media versus bloggers wield inuence in media and pub-

lic agenda-setting. Semantic networks, in which the nodes are words and the ties are

cooccurrences of those words in various media, may be mapped to identify patterns

in how content is framed across dierent outlets over time. ese network approaches

oer promising new methods for research on core media eects theories.

10 SOCIAL NETWORK THEORY

ird, ongoing advances in the statistical approaches used in social network analy-

sis promise continued improvement in the sophistication with which researchers are

able to model how social structure shapes or is shaped by media eects. In particular,

the development of models that allow for multiplex (multiple types of ties), multimode

(multiple types of actors), and multilevel networks enables consideration of greater

complexity in the study of diusion and mediated social inuence. ese developments

are particularly relevant in a new media environment in which actors may be both pro-

ducers and consumers (potentially necessitating multiplex ties), and people may access

content from many dierent types of sources and using many dierent types of media

(requiring multiple modes and levels). In sum, communication research has never been

more promising or relevant, and the theories introduced here oer insights into how to

move communication research forward.

SEE ALSO: Agenda-Setting: Individual-Level Eects Versus Aggregate-Level Eects;

Diusion eories: Logic and Role of Media; Diusion eories: Media as Innovation;

Diusion eories: News Diusion; Multistep Flow of Communication: Evolution of

the Paradigm; Multistep Flow of Communication: Network Eects; Multistep Flow of

Communication: Online Media and Social Navigation; Multistep Flow of Communica-

tion: Opinion Leadership and Personality Strength; Network Society: Networks, Media,

and Eects; Social Networking

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Burt, R. S. (2000). e network structure of social capital. Research in Organizational Behavior ,

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Freeman, L. C. (1977). A set of measures of centrality based on betweenness. Sociometry ,40 (1),

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Granovetter, M. S. (1983). e strength of weak ties: A network theory revisited. Sociological

eory, 1, 210–233. doi: 10.2307/202051

Valente, T. W. (2010). Social networks and health: Models, methods, and applications .NewYork,

NY: Oxford University Press.

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of communication. American Sociological Review, 47, 764–773. doi: 10.2307/2095212

12 SOCIAL NETWORK THEORY

Wenlin Liu is a doctoral candidate at the Annenberg School for Communication,

University of Southern California, USA. Her research interests lie at the intersection

of interorganizational communication and social network theory and methodology.

Wenlin is a research member of the Center for Applied Network Analysis, led by

Dr. omas W. Valente.

Anupreet Sidhu is a doctoral student at the Department of Preventive Medicine, Uni-

versity of Southern California, USA. Her research interests lie in the area of health

campaign evaluation and social networks, specically in health promotion contexts.

Anupreet is a member of the Center for Applied Network Analysis, led by Dr. omas

W. V a l e n t e .

Amanda M. Beacom is a doctoral candidate at the Annenberg School for Communica-

tion, University of Southern California, USA. She conducts research on organizational

communication and social networks, particularly in health contexts.

omas W. Valente is professor in the Department of Preventive Medicine, Univer-

sity of Southern California, USA. He is the author of the books Social Networks and

Health: Models, Methods, and Applications (2010) and Network Models of the Diusion

of Innovation (1995).

... Granovetter's work [10] on Weak Tiestheory demonstrates that a person's weak contacts are more likely to bring novel information such as job opportunities to him compared with his close contacts. Liu et al. [25] discussed the increased online weak ties with the emergence of new media platforms and functions such as "follow the post", and "retweet". Mele [21] proposed a network formation model involving indirect connections, which is an extended version of weak tie. ...

... Following the proof of Theorem 1 and 2, we assume users in one community are independent copies of a single player and reduce the game to a two-player game. We define the two-player stochastic game resulting from Protocol 3 as follows: 1) A state of the game, C (t) , representing the acceptance probability at time t. 2) Actions of red player and blue player p 3) One-stage payoffs for red player and blue player which are the same as (25) and (26), except that the fixed C is substituted by the time-variant C (t) ...

... Combining (42,43) for the additional reward, and (23,24) for the expected utility of users in the game without ARM, we can derive the expected utility of users, i.e., the utility of red and blue player, in (25,26). ...

  • Rui Luo
  • Buddhika Nettasinghe
  • Vikram Krishnamurthy

This paper studies controlling segregation in social networks via exogenous incentives. We construct an edge formation game on a directed graph. A user (node) chooses the probability with which it forms an inter- or intra- community edge based on a utility function that reflects the tradeoff between homophily (preference to connect with individuals that belong to the same group) and the preference to obtain an exogenous incentive. Decisions made by the users to connect with each other determine the evolution of the social network. We explore an algorithmic recommendation mechanism where the exogenous incentive in the utility function is based on weak ties which incentivizes users to connect across communities and mitigates the segregation. This setting leads to a submodular game with a unique Nash equilibrium. In numerical simulations, we explore how the proposed model can be useful in controlling segregation and echo chambers in social networks under various settings.

... These studies acknowledge the powerful influence of social contacts influencing outcomes. More specifically, research about network effects has applied the theory to better understand phenomena in social media such as social media metrics (Peters et al., 2013), mediated information flow (Liu et al., 2017) and personal influences (Katona et al., 2011). Peters et al. (2013) utilized network theory in part to develop guidelines for managing social media. ...

... Peters et al. (2013) utilized network theory in part to develop guidelines for managing social media. Liu et al. (2017) explain network effects based on the integration of three other theories including the two-step flow of communication hypothesis, the theory of weak ties and the theory of diffusion of innovations. ...

Purpose This research tests empirically the level of consumer engagement with a product via a nonbrand-controlled platform. The authors explore how social media influencers and traditional celebrities are using products within their own social media Instagram posts and how well their perceived endorsement of that product engages their network of followers. Design/methodology/approach A total of 226,881 posts on Instagram were analyzed using the Inception V3 convolutional neural network (CNN) pre-trained on the ImageNet dataset to identify product placement within the Instagram images of 75 of the world's most important social media influencers. The data were used to empirically test the relationships between influencers, product placement and network engagement and efficiency. Findings Influencers achieved higher network engagement efficiencies than celebrities; however, celebrity reach was important for engagement overall. Specialty influencers, known for their "subject" expertise, achieved better network engagement efficiency for related product categories. The highest level of engagement efficiency was achieved by beauty influencers advocating and promoting cosmetic and beauty products. Practical implications To maximize engagement and return on investment, manufacturers, retailers and brands must ensure a close fit between the product type and category of influencer promoting a product within their social media posts. Originality/value Most research to date has focused on brand-controlled social media accounts. This study focused on traditional celebrities and social media influencers and product placement within their own Instagram posts to extend understanding of the perception of endorsement and subsequent engagement with followers. The authors extend the theory of network effects to reflect the complexity inherent in the context of social media influencers.

... With the globalisation and the rapid technological growth, new technologies can be used to explore new opportunities for the social network theory, facilitating the contact between organisational members and families, for those who accept international assignments (Liu et al., 2017). The use of a social network is of high importance since its lack of support can lead to superior difficulties in adapting to a new culture (Harry, Dodd and Chinyamurindi, 2019). ...

... When forming those social networks, it is important to consider the members and their positions on the hierarchy. Network cohesion moderates the influence of interpersonal networks, but "personal influence grows stronger within more cohesive social networks" (Liu et al., 2017). ...

  • Adriana Gradim Adriana Gradim

The discussion about expatriation movements has great importance for academic researchers and managers of companies in context of globalization making decisions. The purpose of this work is to understand how the success of the expatriation process depends on a multiplicity of factors. The main aim is to develop a new theoretical framework and metrics to be implemented in different organizational and cultural contexts to enrich the literature on SIE's research field. With this model and its future implementation in various contextual settings, it allows the future development of comparative studies of how human resource management has been globally conducted, considering an internal marketing perspective. Moreover, this work provide better understanding of how global mobility is increasing, why and how to distinguish career paths, suggesting how to identify SIEs. In the final note of this work, strictly theoretical and based on the extensive literature review, the idea is that there is a multiplicity of factors that influence expatriates' decision making. Some of them may be identifiable and measurable, others totally unpredictable and random, suggesting a qualitative assessment before a meaningful and representative group of expatriates.

... Website quality theory (WebQual) is one method of measuring website quality developed by Barnes and Vidgen [30]. The size of web quality can be measured using: Accessibility, Currency, Accuracy and Credibility, can also be measured using information quality: Relevancy, Sufficiency, Understandability, Customer service efficiency: Careful, Continuous, Ease of navigation, Content layout, Ease of use [8], [31], [32]. ...

... External Environment Variables, measured by Government policies relating to entrepreneurship, socio-cultural conditions of society and the role of universities and other related institutions [6], [24], [16], [4] Entrepreneurial Orientation variables are measured based on attitude to innovate, proactive attitudes and risk attitudes [16], [34], [6]. Web Quality Variables are measured based on web accessibility, the accuracy of the information, services and Web security [8], [7], [35], [36], [31]. Variable Business Performance is measured based on market development conditions, development of production and the level of efficiency of respondents [5], [37], [38], [39], [40]. ...

... [30] The size of web quality can be measured using: Accessibility, Currency, Accuracy and Credibility, can also be measured using information quality: Relevancy, Sufficiency, Understandability, Customer service efficiency: Careful, Continuous, Ease of navigation, Content layout, Ease of use. [8], [31], [32]. ...

... External Environment Variables, measured by Government policies relating to entrepreneurship, socio-cultural conditions of society and the role of universities and other related institutions [6], [24], [16], [4] Entrepreneurial Orientation variables are measured based on attitude to innovate, proactive attitudes and risk attitudes [16], [34], [6]. Web Quality Variables are measured based on web accessibility, the accuracy of the information, services and Web security [8], [7], [35], [36], [31]. Variable Business Performance is measured based on market development conditions, development of production and the level of efficiency of respondents. ...

... The theory of social networks identifies the role of social relationships in transferring data, directing personal or media power, and supporting attitudinal or behavioral change [1]. Network studies have become highly important in recent years and now are even more predominate in the fight against the COVID-19 pandemic. ...

Social media has had a strong presence in many people's lives over the last decade. In addition, social media platforms have allowed people to share opinions, provide advice on numerous fac-tors, including where to visit, as well as to stay connected and maintain friendships. The hospital-ity and tourism industry, however, can make effective use of these powerful tools for marketing purposes, collaboration and information sharing, and service offerings. Reviewing social media followers' behaviors and interests offers a wealth of information and valuable data for a variety of tourism organizations. This case study focuses on an analysis of the social networks applied to the fortified town of Fredrikstad in Norway. The data used in this research study were collected from the Facebook site of the tourist authority. The results of this research project demonstrate the strengths of applying a social network analysis to a dataset, which can aid in the strategic direc-tion of a tourism destination. The conversations of the greatest interest can successfully be identi-fied as well as the growth of the online network. This paper adds knowledge to the literature through the application of a social network analysis regarding the success of a tourism destina-tion and its future potential.

... For example, social capital theory (Ellison et al., 2011), social network theory (W. Liu et al., 2017), social support theory (Erfani et al., 2016;Maier et al., 2015), persuasion theory (Westerman et al., 2014), social cognitive theory (DeAndrea et al., 2012) and communication theory (Youmans & York, 2012) have been used extensively to explore the positive potential of OSNs. However, our review revealed far less research on these theories and the negative effects of OSNs. ...

  • Eila Erfani
  • Babak Abedin Babak Abedin

Research on online social networks (OSNs) has focused overwhelmingly on their benefits and potential, with their negative effects overlooked. This study builds on the limited existing work on the so-called 'dark side' of using OSNs. The authors conducted a systematic review of selected databases and identified 46 negative effects of using OSNs from the users' perspective, which is a rich spectrum of users' negative experiences. This article then proposed nomenclature and taxonomy for the dark side of using OSNs by grouping these negative effects into six themes: cost of social exchange, cyberbullying, low performance, annoying content, privacy concerns, and security threats. This study then conducted structured interviews with experts to confirm the sense-making and validity of the proposed taxonomy. This study discusses the confirmed taxonomy and outlines directions for future research.

... Từ đây, các nhà nhân học, xã hội học và các nhà khoa học xã hội nổi tiếng khác như Barnes, Mitchell, George Simmel, Jacos Moreno tiếp tục đi sâu tìm hiểu về mạng lưới xã hội. Nhiều thập niên gần đây, các nhà khoa học thuộc nhiều lĩnh vực như kinh tế học, tâm lý học, khoa học hành vi, thậm chí là các lĩnh vực thiên về tự nhiên như thảm họa thiên nhiên, y tế, sinh thái động vật tiếp tục nghiên cứu chuyên sâu, phát triển, bổ sung hệ thống lý thuyết mạng lưới xã hội với các quan điểm đa chiều và liên ngành (Liu et al., 2017). Tuy nhiên, dù có điểm tương đồng hay khác biệt, song về cơ bản, các nhà nghiên cứu tương đối đồng thuận trong quan niệm về mạng lưới xã hội: ...

Sự kết nối trong lớp học là điều hay được nhắc tới trong các nghiên cứu nhưng rất khó tưởng tượng. Liệu tính kết nối có liên hệ gì với kết quả học tập của sinh viên hay là không. Bài báo này thông qua Phân tích Mạng lưới Xã hội đã mô hình hóa và đo lường tính kết nối giữa các thành viên trong lớp học và mối liên quan tới thành tích học tập của họ. Lớp được nghiên cứu ở đây là một lớp ở bậc đại học và kết quả cho thấy các thành viên có sự kết dính khá cao và không có sự phân tán đáng kể. Kết hợp với việc tính toán chỉ số Pearson (r) trong SPSS, nghiên cứu này đã có phát hiện tương đồng với nhiều nghiên cứu của quốc tế đó là độ kết nối, tính trung tâm của một sinh viên không có tương quan với kết quả học tập. Các kết quả từ bài viết không chỉ cung cấp các gợi ý cho công tác tổ chức lớp học và các hoạt động ngoại khóa mà còn gợi mở các hướng nghiên cứu mới trong lĩnh vực giáo dục ở Việt Nam bằng tư duy mạng lưới.

The COVID-19 pandemic has led to disruption of employee well-being; changing the work scenario across the globe. The psychological impact of this pandemic is an undeniable stressor greatly affecting employee well-being across cultures. Social media, in such a time of crisis, can provide the requisite support by filling the emotional, informational and instrumental voids. In order to explain how reactions to the COVID-19 pandemic influences an individual's employee well-being, this study first examines the relationships between pandemic reactions, social media engagement and employee well-being, and then develops a completely mediated model by fully integrating these links. The results, of structural equation modelling analyses conducted for 304 employees from Hospitality (129) and IT/ITeS sector (175) in India, offered strong support for the proposed model. We found that pandemic reactions were indirectly and positively associated with employee well-being; mediated by social media engagement. This study theoretically contributes to the employee well-being literature by revealing how social media engagement completely mediates the relationship between pandemic reactions and employee well-being. The study also offers practical implications by stressing the significant role played by social media engagement in influencing employee well-being in these testing times.

  • Maha Bashri Maha Bashri
  • Nazar Zaki

Alternative media has provided space for the disenfranchised, where counterhegemony and political practice can take place. Social media platforms have allowed for the formation of new communicative space that disrupts power structures and the established flow of information. This has allowed individuals, who share similar values and ideas, to come together in newly formed public spheres. Furthermore, it has allowed for the emergence of a new type of "social" journalist, who can rally and mobilize audiences around issues beyond the confines of the virtual world. The following study is based on a network analysis of Shaun King's mobilization of followers on Twitter (August 11–13, 2017) after the Unite the Right rally in Charlottesville, Virginia.

  • Ronald S. Burt

Opinion leaders are more precisely opinion brokers who carry information across the social boundaries between groups. They are not people at the top of things so mulch as people at the edge of things, not leaders within groups so much as brokers between groups. The familiar two-step flow of communication is a compound of two very different network mechanisms: contagion by cohesion tl through opinion leaders gets information into a group, and contagion by equivalence generates adoptions within the group. Opinion leaders as brokers bear a striking resemblance to network entrepreneurs in social capital research. The complementary content of diffusion and social capital research makes the analogy productive. Diffusion research describes how opinion leaders play their role of brokering information between groups, and social capital. research describes the benefits that accrue to brokers.

  • Thomas Valente Thomas Valente

Social Networks and Health provides a comprehensive introduction to how social networks influence health behaviors. Section one provides an introduction to major research themes and perspectives used to understand how networks form, evolve, and channel the spread of ideas and behaviors. An intellectual history of the field is provided as well as conjectures on why network science took so long to develop. Methodologies for studying networks and assessing personal network data are discussed. Section two covers algorithms and applications of the most common network metrics divided into four chapters: centrality, groups, positions, and network level. For each chapter, descriptions of how the metrics are calculated and how they influence health behavior are presented. Section three reviews applications of social network analysis to health behaviors. The actor-oriented stochastic evolution model is presented first which provides a way to statistically test network evolution properties. Diffusion of innovations models are presented next which describe how networks influence the spread of ideas and practices within and between communities. Network interventions are also presented and a typology describing network interventions and evidence from empirical studies presented. This book enables researchers to understand how network data are collected and processed; and how to calculate appropriate metrics and models used to understand network influences on health behavior. Simple examples and data are presented throughout so researchers can adopt this methodology and perspective in their own investigations. Examples of health behaviors include smoking, substance use, contraception, HIV/AIDS, obesity, and many others.

  • Ulrik Brandes
  • Jan Hildenbrand

An incredible number of centrality indices has been proposed to date (Todeschini & Consonni, 2009). Four of them, however, can be considered prototypical because they operationalize distinct concepts of centrality and together cover the bulk of analyses and empirical uses: degree, closeness, betweenness, and eigenvector centrality.

  • Ronald S. Burt

This is a review of argument and evidence on the connection between social networks and social capital. My summary points are three: (1) Research and theory will better cumulate across studies if we focus on the network mechanisms responsible for social capital effects rather than trying to integrate across metaphors of social capital loosely tied to distant empirical indicators. (2) There is an impressive diversity of empirical evidence showing that social capital is more a function of brokerage across structural holes than closure within a network, but there are contingency factors. (3) The two leading network mechanisms can be brought together in a productive way within a more general model of social capital. Structural holes are the source of value added, but network closure can be essential to realizing the value buried in the holes.

This special issue presents leading-edge work into how the characteristics of social media affect the nature of influence in networks. Our central thesis is that social influence has become networked influence. Influence is networked in two ways: by occurring in social networks and by propagating through online communication networks. We want to understand online social influence in its diversity: who is exercising influence, how it is done, how to measure influence, what its consequences are, and how online and offline influences intertwine in different contexts.

  • Noah Friedkin Noah Friedkin

I examine the relationship between interpersonal power and influence during the resolution of an issue in an organization. Controlling for elementary bases of power (rewards, coercion, authority, identification, and expertise), I investigate three bases of power that arise from the structure of social networks (cohesion, similarity, and centrality). An analysis of longitudinal data on actors' bases of social power, frequency of interpersonal communications, and interpersonal influences indicates that cohesion, similarity, and centrality have significant effects on issue-related influence net of the elementary power bases. The effects of the structural bases are mediated by the frequency of issue-related communication. The primary structural determinant of the frequency of issue-related communication is network cohesion.