Social Network Blog - g3

The Wasserman and Faust article explained the roles and elements of centrality and prestige in networks. The power of an individual in a network is based on his or her “actor location”, which is “actors who are the most important or the most prominent are usually located in strategic locations within the network” (169). Depending on the number of ties an individual has within a network, whether these ties are reciprocated (determined by outdegree and indegree), whether they are directional (yielding directed graphs) or not, and various other determining factors. Using various equations, that sometimes go over a reader’s head, Wasserman and Faust measured the centrality and prestige of an actor in terms of degree of closeness, proximity, betweenness, information, and differential status or rank of the actors and the group they are included in. I found the use of the three artificial graphs was extremely helpful. To clarify several of the points better, I related each type to “famous” networks. Wasserman and Faust described the connections in each network as: “All nodes in the circle are interchangeable, and hence should be equally central. One node in the star completely outranks the others, while the other six themselves are interchangeable. In the line graph, the nodes’ centrality clearly decreases from that for n1, to n2 and n3, and so on to n6 and n7, who are peripheral in this graph” (171). The network I envisioned for the circle graph was akin to the sitcomFriends, each friend was of equal value. The star network was certainly closest to Mean Girl or any teen movie with a popular clique (She’s All That, where one girl was the central leader, and had a band of followers. However, I found difficulty in related the line graph to its perfect media match. What sitcom/movie best describes a line relationship? The central figure of a star relationship serves as what I would see as a ideal version of an opinion leader, imposing an idea to be picked up by other members. An interesting anecdote that best shows the opinion leading nature of the central node refers to the shopping world and girls. A friend of mine worked in a retail store in L.A. Part of his role working on the floor was to pick out the “Alpha female” (the central node). By helping this girl find the “perfect outfit”, he was helping the entire group as well, because they would listen in on what their “Alpha female” would find fashionable, then copy in their own manner. Thus, by influencing the central node, he was influencing the “gaggle of girls.”

The article by Freeman was very similar to the Wasserman and Faust article. There were the shared explanations about the centrality of nodes, especially using my “Alpha female”/ star example. Freeman also uses a great amount of equations, like Wasserman and Faust, and actually comes of a it more complicated, perhaps due to the repetitive nature of this article. Freeman focuses on the how centrality is determined by group structure, efficiency, and complexity. (The later readings reference his article to use the equations of determined centrality.)

Valente et al. studied whether there is a considerable association between degree of popularity and the smoking behavior of adolescents. Within the 1990s, a noticeable increase has occurred in the prevalence of smoking among high school seniors, which is counter to the decreasing rates found from the late 1970s through to the mid 1980s. However, it is also found that within cultures that have widespread smoking, peers will promote smoking. But in cultures that view smoking as unpopular, peers will dissuade adolescents from smoking. Isolates, who were beyond the bonds of friendship, were found to become smokers as well, therefore they had an opposite effect of peer influence. There was a significant finding in the study that increased susceptibility was associated with popularity but an adjusted odds ratio. It was also found that the most susceptible to smoke were those who had a higher number of students the respondents (highest number of out-degree friendships). One interesting fact found that was found was that this study’s social network survey was based in schools that had curriculum on smoking prevention (not in the control schools). The survey was administered in this manner so as not to be confounded by program effects, since it was conducted in the context of an intervention designed to slow smoking uptake. Do you believe that there might be a major effect on the results of the study because the survey was administered to students who were taught about the harmful effects of smoking? Would students answer differently after receiving lectures on the subject matter, and thus find the topic sensitive and not answer truthfully?

Krebs created an interesting study focused on terrorist networks. Due to the sensitive nature of the study, it was designed as an observational study instead of an experimental research study. The researcher performed a content analysis, through the countless reports on the matter of 9/11 that focused on the networks of those involved in 9/11. Although these terrorists appeared to be on a mission simply for Al Qaeda, thus there was a high degree of secrecy, further investigation revealed that the terrorists involved were connected through an intricate knowledge sharing network. Meetings in Las Vegas and ties to more Al Qaeda had created an even more intricate network of ties to other terrorists. Figure 4 exhibits the network of those connected to hijackers. Mohamed Atta displays a relationship in this terrorist network that is highly prominent and centralized. He appears to be “extensively involved in the relationships of other actors” (Wessman 173). According to the network’s centrality metrics of degrees, closeness, and betweenness, he scored the highest of all. Thus, his image as a leader was supported. Due to these factors, Atta is centralized and can influence others in the network, while also safeguarding the secrecy of this terrorist network.

The Mouttapa et al studied the relationship popularity has with bullying and victimization. The popular area of Southern California, used in many studies before (this week’s smoking study, Kilworth article), is focused on in this study, looking at a sample of 1368 6th graders, who are primarily Latino and Asian. This study exhibits an excellent example of indegree and outdegree networks. For example, female bullies(who are involved with the rumor spreading type of bullying) had a very high proportion of reciprocated friendships, but had fewer friendship nominations. Thus, they have less central network positive, but have strong ties to their friends. Bullies and aggressive victims tend to nominate friends who are also aggressive (326). Victims were found to have fewer social connections relative to other students, consistent with the dominancy theory. Overall, this study expanded past the traditional demographic populations that have been studied, and applied centrality to an excellent example.