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The Critical Periphery in the Growth of Social Protests.

Barberá P, Wang N, Bonneau R, Jost JT, Nagler J, Tucker J, González-Bailón S - PLoS ONE (2015)

Bottom Line: Although committed minorities may constitute the heart of protest movements, our results suggest that their success in maximizing the number of online citizens exposed to protest messages depends, at least in part, on activating the critical periphery.Peripheral users are less active on a per capita basis, but their power lies in their numbers: their aggregate contribution to the spread of protest messages is comparable in magnitude to that of core participants.Theoretical models of diffusion in social networks would benefit from increased attention to the role of peripheral nodes in the propagation of information and behavior.

View Article: PubMed Central - PubMed

Affiliation: Center for Data Science, New York University, New York, New York, 10003, United States of America.

ABSTRACT
Social media have provided instrumental means of communication in many recent political protests. The efficiency of online networks in disseminating timely information has been praised by many commentators; at the same time, users are often derided as "slacktivists" because of the shallow commitment involved in clicking a forwarding button. Here we consider the role of these peripheral online participants, the immense majority of users who surround the small epicenter of protests, representing layers of diminishing online activity around the committed minority. We analyze three datasets tracking protest communication in different languages and political contexts through the social media platform Twitter and employ a network decomposition technique to examine their hierarchical structure. We provide consistent evidence that peripheral participants are critical in increasing the reach of protest messages and generating online content at levels that are comparable to core participants. Although committed minorities may constitute the heart of protest movements, our results suggest that their success in maximizing the number of online citizens exposed to protest messages depends, at least in part, on activating the critical periphery. Peripheral users are less active on a per capita basis, but their power lies in their numbers: their aggregate contribution to the spread of protest messages is comparable in magnitude to that of core participants. An analysis of two other datasets unrelated to mass protests strengthens our interpretation that core-periphery dynamics are characteristically important in the context of collective action events. Theoretical models of diffusion in social networks would benefit from increased attention to the role of peripheral nodes in the propagation of information and behavior.

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Schematic representation of the k-core decomposition for a random network with N = 16 vertices and E = 24 edges.This technique recursively prunes the network to remove nodes with the lowest degree. The coreness of a vertex is k if it belongs to the k-core but not to the (k+1)-core.
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pone.0143611.g002: Schematic representation of the k-core decomposition for a random network with N = 16 vertices and E = 24 edges.This technique recursively prunes the network to remove nodes with the lowest degree. The coreness of a vertex is k if it belongs to the k-core but not to the (k+1)-core.

Mentions: We identify core and peripheral participants using the k-core decomposition technique, which partitions a network in nested shells of connectivity [27, 28]. The k-core of a graph is the maximal subgraph in which every vertex has at least degree k. In our case, degree relates to the number of retweets made or received. The k-core decomposition is a recursive approach that progressively trims the least connected nodes in a network (i.e. those with lower degree) in order to identify the most central ones. Fig 2 illustrates the k-core decomposition of a random graph with 19 vertices and 24 edges. Node degree is in the range of 1 to 5, but there are only four cores. Since the method is recursive, some of the nodes with degree 5 end up being classified in lower k-shells. Nodes classified in higher k-shells not only have higher degree: they are also connected to nodes that are central as well. Low engagement participants are classified in lower k-shells, and they form the periphery of the network.


The Critical Periphery in the Growth of Social Protests.

Barberá P, Wang N, Bonneau R, Jost JT, Nagler J, Tucker J, González-Bailón S - PLoS ONE (2015)

Schematic representation of the k-core decomposition for a random network with N = 16 vertices and E = 24 edges.This technique recursively prunes the network to remove nodes with the lowest degree. The coreness of a vertex is k if it belongs to the k-core but not to the (k+1)-core.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664236&req=5

pone.0143611.g002: Schematic representation of the k-core decomposition for a random network with N = 16 vertices and E = 24 edges.This technique recursively prunes the network to remove nodes with the lowest degree. The coreness of a vertex is k if it belongs to the k-core but not to the (k+1)-core.
Mentions: We identify core and peripheral participants using the k-core decomposition technique, which partitions a network in nested shells of connectivity [27, 28]. The k-core of a graph is the maximal subgraph in which every vertex has at least degree k. In our case, degree relates to the number of retweets made or received. The k-core decomposition is a recursive approach that progressively trims the least connected nodes in a network (i.e. those with lower degree) in order to identify the most central ones. Fig 2 illustrates the k-core decomposition of a random graph with 19 vertices and 24 edges. Node degree is in the range of 1 to 5, but there are only four cores. Since the method is recursive, some of the nodes with degree 5 end up being classified in lower k-shells. Nodes classified in higher k-shells not only have higher degree: they are also connected to nodes that are central as well. Low engagement participants are classified in lower k-shells, and they form the periphery of the network.

Bottom Line: Although committed minorities may constitute the heart of protest movements, our results suggest that their success in maximizing the number of online citizens exposed to protest messages depends, at least in part, on activating the critical periphery.Peripheral users are less active on a per capita basis, but their power lies in their numbers: their aggregate contribution to the spread of protest messages is comparable in magnitude to that of core participants.Theoretical models of diffusion in social networks would benefit from increased attention to the role of peripheral nodes in the propagation of information and behavior.

View Article: PubMed Central - PubMed

Affiliation: Center for Data Science, New York University, New York, New York, 10003, United States of America.

ABSTRACT
Social media have provided instrumental means of communication in many recent political protests. The efficiency of online networks in disseminating timely information has been praised by many commentators; at the same time, users are often derided as "slacktivists" because of the shallow commitment involved in clicking a forwarding button. Here we consider the role of these peripheral online participants, the immense majority of users who surround the small epicenter of protests, representing layers of diminishing online activity around the committed minority. We analyze three datasets tracking protest communication in different languages and political contexts through the social media platform Twitter and employ a network decomposition technique to examine their hierarchical structure. We provide consistent evidence that peripheral participants are critical in increasing the reach of protest messages and generating online content at levels that are comparable to core participants. Although committed minorities may constitute the heart of protest movements, our results suggest that their success in maximizing the number of online citizens exposed to protest messages depends, at least in part, on activating the critical periphery. Peripheral users are less active on a per capita basis, but their power lies in their numbers: their aggregate contribution to the spread of protest messages is comparable in magnitude to that of core participants. An analysis of two other datasets unrelated to mass protests strengthens our interpretation that core-periphery dynamics are characteristically important in the context of collective action events. Theoretical models of diffusion in social networks would benefit from increased attention to the role of peripheral nodes in the propagation of information and behavior.

Show MeSH