567
个编辑
更改
跳到导航
跳到搜索
第1行：
第1行： + + + + − Complex contagion is the phenomenon in social networks in which multiple sources of exposure to an innovation are required before an individual adopts the change of behavior. Centola and Macy show that the weak ties and small worlds networks are both very good for spreading simple contagions. However, for complex contagions, weak ties and small worlds can slow diffusion.+ − '''复杂传染 Complex contagion'''是[[社会网络]]中的一种现象，在社会网络中，一个人或一个个体需要受到多种不同的影响，会对自身行为采取改变。<ref name="CENTOLA" /> 不同于疾病的简单传染，邻居单一的一次接触并不会使其成功传染，复杂传染的传播需要人群网络中复杂交错的社会和经济因素。例如，一个人有多少个朋友接受这个新想法，以及这些朋友能不能影响这个人，以及他们自己接受改变的倾向。Centola和Macy表明，弱联系和小世界网络都非常有利于简单传播的传染病。然而，对于复杂传染，弱联系和小世界可以有效减缓扩散。+ − ==传播机制== − These properties explain the need for multiple exposures in the spread of contagion:+ − Centola和Macy梅西提出了四种复杂传染的机制。这些性质解释了在传染过程中为什么需要多重曝光：+ − + + + − Strategic complementarity. Many innovations are costly, especially for early adopters but less so for those who wait. The same holds for participation in collective action.+ − 战略互补性。许多创新成本高昂，尤其是对于早期采用者，但对于那些等待的人来说成本较低。参与集体行动也是如此。+ − Centola and Macy suggest four mechanisms of complex contagion. These properties explain the need for multiple exposures in the spread of contagion:+ + − Credibility. Innovations often lack credibility until adopted by neighbors. Hearing the same story from different people makes it seem less likely that surprising information is nothing more than the fanciful invention of the informant.+ − 可信度。创新往往缺乏可信度，直到被邻居采用。从不同的人那里听到同样的故事，使得令人惊讶的信息不过是线人幻想出来的东西的可能性降低了。+ + + + + − Legitimacy. Knowing that a movement exists or that a collective action will take place is rarely sufficient to induce bystanders to join in. Having several close friends participate in an event often greatly increases an individual’s likelihood of also joining, especially for high-risk social movements. Innovators risk being shunned as deviants until there is a critical mass of early adopters, and non-adopters are likely to challenge the legitimacy of the innovation.+ + − 合法性。知道一个运动的存在或者一个集体行动将要发生，很少足以诱使旁观者加入进来。有几个亲密的朋友参加一个活动通常会大大增加一个人加入的可能性，特别是对于高风险的社会运动。创新者可能会被当作异类回避，直到有足够数量的早期采用者，而非采用者可能会挑战创新的合法性。+ + − #''Strategic complementarity.'' Many innovations are costly, especially for early adopters but less so for those who wait. The same holds for participation in [[collective action]].+ + − Emotional contagion. Most theoretical models of collective behavior – from action theory to threshold models to cybernetics share the basic assumption that there are expressive and symbolic impulses in human behavior that can be communicated and amplified in spatially and socially concentrated gatherings.+ + − 情绪感染。从行动理论到门槛模型再到控制论，大多数集体行为的理论模型都有一个共同的基本假设，即人类行为中存在着表达冲动和象征冲动，这些冲动可以在空间和社会集中的集会中得到沟通和放大。+ + − #''Credibility.'' Innovations often lack credibility until adopted by neighbors. Hearing the same story from different people makes it seem less likely that surprising information is nothing more than the fanciful invention of the informant.+ + − #''Legitimacy.'' Knowing that a movement exists or that a collective action will take place is rarely sufficient to induce bystanders to join in. Having several close friends participate in an event often greatly increases an individual’s likelihood of also joining, especially for high-risk [[social movement]]s. Innovators risk being shunned as [[deviant]]s until there is a critical mass of early adopters, and non-adopters are likely to challenge the legitimacy of the innovation.+ − #''[[Emotional contagion]].'' Most theoretical models of [[collective behavior]] – from [[Action theory (sociology)|action theory]] to [[threshold model]]s to [[cybernetics]] share the basic assumption that there are expressive and symbolic impulses in [[human behavior]] that can be communicated and amplified in spatially and socially concentrated gatherings.<ref name="CENTOLA" />+ + + + + + + + − + − + − + − :The spread of the contagion is dependent solely on the number of people you are connected to who are different from your own state. You are not hindered whatsoever by the number of people in the same state as you. Generally, the more neighbors an individual has, the greater the chance of the individual adopting the innovation if the spread is uncontested.<ref name="CENTOLA" />+ − + − }} − − }} − − − − − − − − − − Category:Social networks − − 分类: 社交网络 − − <noinclude> − − <small>This page was moved from [[wikipedia:en:Complex contagion]]. Its edit history can be viewed at [[复杂传染/edithistory]]</small></noinclude>
无编辑摘要
'''复杂传染 Complex contagion'''是社会网络中的一种现象，在社会网络中，一个人或一个个体需要受到多种不同的影响，会对自身行为采取改变。 不同于疾病的简单传染，邻居单一的一次接触并不会使其成功传染，复杂传染的传播需要人群网络中复杂交错的社会和经济因素。例如，一个人有多少个朋友接受这个新想法，以及这些朋友能不能影响这个人，以及他们自己接受改变的倾向。
== 传播机制 ==
宾夕法尼亚大学的Damon Centola和康奈尔大学的Michael Macy合著的《复杂传染和长纽带的弱点'''''Complex Contagion and the Weakness of Long Ties''''' 》发现，信息和疾病以“简单传染”的方式传播，只需要一次接触就能传播，而其传播行为通常以“复杂传染”的方式传播，这通常需要多种不同的来源的强化来使其感染。Centola的工作建立在Granovetter关于弱联系的力量和集体行为的阈值模型的工作，以及邓肯·瓦茨 Duncan J. Watts和斯蒂文·斯特罗加茨 Steven H. Strogatz关于小世界网络的工作的基础上。Centola和Macy表明，弱联系和小世界网络都非常有利于简单传播的传染病。然而，对于复杂传染，弱联系和小世界可以有效减缓扩散。
Centola和Macy梅西提出了四种复杂传染的机制，这些性质解释了在传染过程中为什么需要多次不同来源的强化：
* '''战略互补性 Strategic Complementarity'''
许多创新的成本高昂，尤其是对于早期采用者，但对于那些较晚采用的人来说成本较低。参与集体行动也是如此。
* '''可信度 Credibility'''
创新往往缺乏可信度，直到被他人采用。从不同的人那里听到同样的故事，会更有说服力。
'''''Complex Contagion and the Weakness of Long Ties''''' by [[Damon Centola]] of [[University of Pennsylvania]] and [[Michael Macy]] of [[Cornell University]] found that information and disease spread as “simple contagions”, requiring only one contact for transmission, while behaviors typically spread as “complex contagions”, requiring multiples sources of reinforcement to induce adoption. Centola’s work builds on [[Mark Granovetter|Granovetter’s work]] on the strength of weak ties and threshold models of collective behavior, as well as [[Duncan J. Watts|Duncan Watts]] and [[Steven Strogatz|Steve Strogatz’s]] work on small world networks.<ref>http://science.sciencemag.org/content/329/5996/1194</ref> Centola and Macy show that the weak ties and small worlds networks are both very good for spreading simple contagions. However, for complex contagions, weak ties and small worlds can slow diffusion.
* '''合法性 Legitimacy'''
知道即将有一个集体行动的发生，很少会使旁观者加入进来。而知道有几个亲密的朋友要参加一个活动通常会大大增加一个人加入的可能性，特别是对于有高风险的社会运动。创新者可能会被当作异类回避，直到有足够数量的早期采用者，而非采用者可能会挑战创新的合法性。
* '''情绪感染 Emotional Contagion'''
从行动理论到阈值模型再到控制论，大多数集体行为的理论模型都有一个共同的基本假设，即人类行为中存在着表达冲动和象征冲动，这些冲动可以在空间和社会集中的集会中得到沟通和放大。
== 争议性 ==
=== 无争议性 ===
传染病的传播仅仅取决于你所联系的人的数量，他们与你自己的状态不同。你不会因为和你处于同一状态的人的数量而受阻。一般来说，如果传播没有争议，一个人的邻居越多，这个人采用创新的机会就越大。
;
=== 有争议性 ===
传染的传播既依赖于那些与你处于不同状态的人的坚持，也依赖于那些与你当前状态相同的人的抵消影响。在这种情况下，一个个体拥有的邻居越多，该个体采用该创新的机会越小。
== 网络中的扩散和级联行为 ==
See also: Global cascades model
Consider a graph of any reasonable size. Node v’s neighbors can be split into two sets: Set A contains v's neighbors who have adopted a new behavior and B is the set of those behaving conservatively. Node v will only adopt the behavior of those in A if at least a ''q'' fraction of neighbors follow behavior A.
* if ''q'' is small, the behavior is easily adopted and easily spread
* if ''q'' is large, B is an attractive behavior and it takes more friends to engage in A before v will switch.
; Cascading – diffusion over the entire network
: Consider a set of initial adopters who start with a new behavior A, while every other node starts with behavior B. Nodes then repeatedly evaluate the decision to switch from B to A using a threshold of ''q''. If the resulting cascade of adoptions of A eventually causes every node to switch from B to A, then we say that the set of initial adopters causes a complete cascade at threshold ''q''. Clusters of density ''d'' > 1 − ''q'' are obstacles to cascades across the entire network.
=== 参见:全局级联模型 ===
考虑任意大小的图，节点v的邻居可以分成两个集合：集合A包含v中采用新行为的邻居，集合B是行为保守的邻居的集合。只有当至少''q'' 个邻居遵循行为A时，节点v才会采用A中邻居的行为。
* 如果 ''q'' 很小，这种行为很容易被采纳，也很容易传播。
* 如果 ''q'' 很大，B是一种吸引的行为，需要更多的朋友参与到A中，v才会转换。
=== 整个网络上的级联-扩散 ===
考虑一组初始用户开始新的行为A，而其他节点从行为B开始。节点使用一个阈值''q''反复的评估决定从B到A的转化。如果最终由此产生的每个节点都从B切换到A，那么我们说，初始用户的集合在阈值''q'' 处导致了一个完整的级联，我们称整个网络级联的障碍是当其密度为''d'' > 1 − ''q'' 时。
== 应用案例 ==
许多互动发生在局部层面，而不是整体层面——我们往往不像关心朋友和同事所做的决定那样关心整个群体的决定。例如，在工作环境中，我们可能会选择与我们直接合作的人兼容的技术，而不是全局流行的技术。同样，我们可能会采取与我们的朋友一致的政治观点，即使他们属于少数群体。
=== 案例 ===
* The credibility of an urban legend 都市传说的可信度
* Willingness to participate in migration – (participating in a collective action)参与移民的意愿-(参与集体行动)
* Incentives to exit formal gatherings退出正式聚会的动机
* Lifestyle trends: What clothing to wear, hairstyle to adopt, and what part of the body to pierce.生活方式:穿什么衣服，留什么发型，穿什么部位。
* The adoption of political hashtags on Twitter. 在推特上使用政治标签。
=== 简单传播的案例 ===
* 疾病的传播
* 信息的传播
==Contested vs. uncontested==
== References ==
;Uncontested
# ^ Jump up to:<sup>'''''a'''''</sup> <sup>'''''b'''''</sup> <sup>'''''c'''''</sup> <sup>'''''d'''''</sup> <sup>'''''e'''''</sup> <sup>'''''f'''''</sup> Centola, Damon; Macy, Michael. "Complex Contagions and the Weakness of Long Ties." University of Chicago, 2007.
# '''^'''
# ^ Jump up to:<sup>'''''a'''''</sup> <sup>'''''b'''''</sup> <sup>'''''c'''''</sup> <sup>'''''d'''''</sup> Easley, David; Kleinberg, Jon. ''Networks, Crowds, and Markets: Reasoning about a Highly Connected World.'' Cambridge University Press, 2010.
# '''^''' ''Differences in the mechanics of information diffusion across topics | Proceedings of the 20th international conference on World wide web''. ''dl.acm.org''. WWW '11. 28 March 2011. pp. 695–704. doi:10.1145/1963405.1963503. ISBN <bdi>9781450306324</bdi>. S2CID 207186115. Retrieved 2020-08-11.
;Contested
:The spread of the contagion is dependent on both the adamancy of those who are in a different state from your own as well as the countervailing influence of those who share your current state. In this case, the more neighbors an individual has, the smaller the chance of the individual adopting the innovation.<ref name="CENTOLA" />
[[Category:待整理页面]]
[[Category:待整理页面]]