Visualización: Tópicos compartidos por los noticieros estadounidenses

U.S. News Outlets - Network of Shared Topics

Katherine Ognyanova

Doctoral Candidate at University of Southern California, Annenberg

ognyanova@usc.edu

News Ties: A Study of Media-Level Agenda-Setting

Self-Commentary

The research presented here proposes an exploration of inter-media agenda-setting. One of the big questions in the field is whether proliferation of channels and information overload have fragmented news content, rendering the idea of a consistent mainstream media agenda obsolete. The study employs network analysis methods to test this proposition. News outlets are seen as a set of interconnected nodes with ties based on overlap of issue coverage. Two news sources are linked if there is an above average similarity in their selection of topics over a period of time. The research demonstrates that mainstream media outlets not only have overlapping agendas at a given point in time, but also exhibit patterns of shared coverage that persist over time. A QAP analysis comparing networks of shared topics compiled for January and December of 2007 shows a strong and significant correlation (r=0.87, p<0.001) between the two. Furthermore, both networks are dense, well-connected and have a relatively high centralization index - something that goes against the idea of fragmentation and disintegration of media agenda.

The study goes on to explore the set of properties that are likely to influence the overlap of media agendas. Factors taken into consideration include format (newspaper, radio, network TV, cable TV, Internet), common ownership, and volume of the outlet production. An ERG model including parameters for those factors as well as basic structural signatures is fitted to the December 2007 news outlet network. Results of the estimation indicate that both production volume and common ownership affect the topic overlap of news outlets. In order to investigate the patterns of shared coverage within and across media sectors, a blockmodel analysis is performed (results presented on the figure above). Network TV, Internet and radio outlets are likely to produce coverage similar to that of other media of the same type. This does not hold true for newspapers and cable TV. The Network TV outlets have dense ties with all of the other four sectors – a finding consistent with previous research on the influence of television news.

PEER REVIEW COMMENT No. 1

This submission shows the topic similarity between news outlets, where a tie exists if two organizations cover a similar array of topics.  The pairing of the block-model results and the detail graph is very helpful, as the detailed layout is so dense as to make identifying positions challenging.    I wonder if the image would be improved by forcing the nodes into a positioning more similar to the block layout or somehow incorporating a weighting that differentiates within and between-block ties? 

PEER REVIEW COMMENT No. 2

The visualization uses a block-modeling approach to show that despite a proliferation of media outlets, there is much convergence on news topics. While the block model image portrays a general sense of the interconnectedness of the media system, the network image itself is somewhat swamped by density of ties, with little information aside from the size and centrality of the media outlet evident from the detailed image.   The rendering itself is nicely done, with a color scheme that is easy to view and differentiate. 

PEER REVIEW COMMENT No. 3

This visualization has excellent theoretical framing, providing an interesting question, and an easily understood visual answer.  The blockmodel and adjacency plots compliment each other well, and give us both a sense of connectedness and structure.  The use of loops in the blockmodel is especially effective at giving us a sense of internal connectedness compared to connectedness between.  I'd be interested to see a hybrid of the blockmodel and adjacency views.

JoSS

Brandes y Pich (2013): Visualización exploratoria de patrones de citas en investigación de redes sociales

Brandes - Explorative Visualization of Citation Patterns in Social Network Research

Publish at Calameo or read more publications.

Visualización: Enlaces dentro y entre 5 posiciones equivalentes en el comercio de productos agrícolas

Ties within and between the 6 regularly equivalent positions in the trade of agricultural products

Carl Nordlund

Lund University

carl.nordlund@hek.lu.se

Ties Within and Between the 6 Regularly Equivalent Positions in the Trade of Agricultural Products

 

Figure 8.11: Ties within and between the 6 regularly equivalent positions (applying criteria fulfillment formula 1 with a relative cutoff value of ~0.0102 (1/98)).

Self-Commentary

The diagram above is a structural map of international flows of agricultural hectares (aka ‘ecological footprints’) between 1995-99. Countries are categorized according to their sharing of similar regular roles in the trade of agricultural products. Positions are determined using multi-dimensional scaling on the matrix containing REGE coefficients, whereas arrows indicate regular ties depicted using a criteria-fulfillment heuristic developed for datasets with huge value spans (Nordlund 2007).

Ties within and Between 8 Regularly Equivalent Positions

Figure 9.8: Ties within and between the 8 regularly equivalent positions: forestry commodity biomass flows (applying criteria fulfillment formula 1 with a relative cutoff value of ~0.0112 (1/89)).

                Similar to the first diagram, the above second figure is a structural map of international flows of timber biomass during the 1995-99 period. Determining role-equivalence through the REGE algorithm, the resulting structural map depicts a structure where a dual core controls the network of forestry product trade.

                Both diagrams are taken from Ecography; International trade, network analysis, and ecological conceptualizations of unequal exchange – my PhD thesis in human ecology (Lund university, Sweden), to be published in August-September 2009.

PEER REVIEW COMMENT No. 1

The visualization above depicts the international flows of agricultural and forestry products. The vast web of trade is simplified by placing countries in regular equivalent roles and mapping the relations across the roles.  It is clear from the second graph that the forestry trade network exhibits a dual core structure, where two sets of regularly equivalent countries are at the core of the network. The regular equivalence graph nicely simplifies a very complicated network.  The image itself is difficult to use in stand-alone form, since too much is assumed of the viewer. It is not clear, for example, what the "criteria fulfillment" actually is and why it is important, so some simple explanatory work there might be helpful.

PEER REVIEW COMMENT No. 2

This visualization is a depiction of the role structure of an international trade network. While this image provides an excellent concentration of a large amount of information, it is lacking a clear interpretation.   As a model of the world system, it would help if there were a simple way to compare the two contents of trade represented in the two figures. I find myself comparing the country codes of the two cores, to see who is left out in each.

PEER REVIEW COMMENT No. 3

This submission provides a great structural view of the data, without obscuring the identities of individual nodes.  I wonder if the node identities can be arrayed to provide additional information, without detracting from the structural clarity provided in an REGE-based diagram.

Journal of Social Structure

Argentina el 25% de las cuentas twittean 2% menos que la media mundial

Los países más activos en Twitter


De media, tan sólo una de cada cuatro cuentas en Twitter mantiene actividad de forma regular. Esta cifra, no obstante, varía notablemente en función de determinados países.

Según Semiocast, España es uno de los 3 países más activos en la red social del mundo. El 29% de las cuentas de este país twittean con frecuencia, un 2% por encima de la media mundial.

Los Países Bajos y Japón nos adelantan con un 33% y un 30% de cuentas con actividad frecuente, respectivamente. Estados Unidos, por el contrario, ha quedado relegado al cuarto puesto, con un 28% de actividad regular.

Alemania, Filipinas y la India se encuentran a la cola de este particular ranking, en donde la diferencia con respecto a la media mundial puede llegar a ser de hasta un -8%.

Ranking:

MathMen

La empatía como una elección

Empathy as a choice

By Jamil Zaki

About 250 years ago, Adam Smith famously described the way observers might feel watching a tightrope walker.  Even while standing on solid ground, our palms sweat and our hearts race as someone wobbles hundreds of feet in the air (you can test this out here).  In essence, we experience this person’s state as our own.

Centuries later, this definition does a surprisingly good job at capturing scientific models of empathy.  Evidence from across the social and natural sciences suggests that we take on others’ facial expressions, postures, moods, and even patterns of brain activity.  This type of empathy is largely automatic.  For instance, people imitate others’ facial expressions after just a fraction of a second, often without realizing they’re doing so. Mood contagion likewise operates under the surface.  Therapists often report that, despite their best efforts, they take on patients’ moods, consistent with evidence from a number of studies.

One tempting conclusion about automatic behaviors is that are also “dumb:” occurring whenever the right stimulus comes along.  On this view, empathy is the emotional equivalent of a patellar reflex: while observing someone’s emotions, you can’t help but take those emotions on yourself.  Intuitive as it may be, a “reflex model” glosses a vital feature of empathy: it is often a choice.  Even if others’ emotions rub off on us automatically, this process is only set in motion if we decide to put ourselves in a position for empathy to occur.  And that decision is anything but automatic.  Instead, people frequently make deliberate choices to avoid others’ emotions, in attempts to stave off the discomfort or costs of empathy.

One of my favorite studies on this topic—a long forgotten gem from 1979—measured empathy by circumference.  Mark Pancer and his colleagues set up a table in a busy tunnel at the University of Saskatchewan, and secretly measured the distance people kept from the table while walking past.  They manipulated two features of the situation.  The first was whether or not the table had a box placed on it requesting charitable donations.  The second was who was manning the table: (i) no one, (ii) an undergraduate, or (iii) an undergraduate sitting in a wheelchair.  Both the request to donate and the presence of a handicapped person were considered triggers to empathy.  Instead of approaching these triggers, however, students avoided them: walking a wider arc around the table in the presence of either trigger, and keeping the greatest distance in the face of both the handicapped student and donation box.

In a more recent study along the same lines, Daryl Cameron and Keith Payne examined the well-known “collapse of compassion.” Cameron and Payne told participants about the suffering of children in the wake of Darfur’s civil war, and showed them pictures of either one or eight of these children.  Critically, they told some participants that—after viewing these pictures—they would have a chance to donate money to help these children.  Participants who believed they would be put on the spot to donate felt less empathy for eight children than for one, consistent with the idea that they purposefully “turned down” their empathy when empathizing could prove costly.

Together, these studies suggest that instead of automatically taking on others’ emotions, people make choices about whether and how much to engage in empathy.  Pancer and Cameron’s observations at first appear bleak—people shut down empathy when it might cost them—but I think they paint a more encouraging picture.  For instance, Paul Bloom recently argued that empathy is a bad guide for decision-making, precisely because it is a slave to triggers such as images of others’ suffering.  On Bloom’s reasoning, this means that empathy will often drive irrational choices based on emotions: for instance, helping a single suffering child we see on television while ignoring countless others who receive less press.  Although Bloom is right in many cases, if empathy is a choice, then people can presumably learn to use it when they know it is most important.  For instance, people could decide to “turn up” empathy for victims with whom they might not immediately connect (a suggestion made earlier by Daryl Cameron as well).  Broadly speaking, empathy we can control is empathy we can co-opt to help others as much as possible.

Scientific American

About the Author: Jamil Zaki is an assistant professor of psychology at Stanford University, studying the cognitive and neural bases of social cognition and behavior. Follow on Twitter @jazzmule.

¿Tener amigos (monos) incrementa el tamaño de tu cerebro?

Social Networks Matter: Friends Increase the Size of Your Brain

By Eric Michael Johnson 

Scientific American

New research confirms that social complexity enriches cognitive growth. Could having more Facebook friends actually make you smarter?

"The Social Network" by Nathaniel Gold

   

Let’s face it, as a species we’re obsessed with ourselves. The vast majority of us spend our days at work or school where a considerable amount of time is taken up not discussing the important issues of the day, but rather the juicy details of one another’s personal lives. Then we go home only to sign on to social network services like Facebook, Twitter, orGoogle+ and continue where we left off. In this respect we’re fairly typical primates. Most of our simian relatives, particularly our great ape cousins the chimpanzees and bonobos, like nothing better than keeping a watchful eye on what other members of their troop are up to. But our species has taken this preoccupation one step further.

Human beings are the most social of the primates and have the largest group sizes of any species in our order. For about 90% of our existence we lived in hunter-gatherer societies with populations that likely clustered around 150-200 individuals. By way of comparison, baboons come in a distant second with an average of about 50 group members. Now, thanks to modern industrial agriculture, our species has pushed that range well into the millions, a development that has resulted in considerable stress on our slightly above average primate brains. Of course, all organisms need to successfully predict and navigate their environments in order to relay their genes on to the next generation. It’s just that this becomes increasingly complicated when there are many individuals all interacting in the same environment simultaneously. Merely keeping track of these relationships requires a considerable amount of time and energy, not to mention brain power.

In the 1990s the British evolutionary anthropologist Robin Dunbar championed an idea known as the Social Brain Hypothesis. He found that mammals who lived in the largest social groups often had the largest neocortex to brain ratio. Since the neocortex — composed chiefly of gray matter that forms the outermost “rind” of our cantaloupe-sized stuff of thought — is associated with sensory perception and abstract reasoning, Dunbar hypothesized that the demands of group living resulted in a selection pressure that promoted the expansion of neocortical growth.

Figure 1. As average group size increases in monkeys and apes, so does neocortex ratio. Reproduced from Dunbar and Shultz (2007).

In 2009 I co-authored a study in the Journal of Human Evolution with colleagues Evan MacLean, Nancy Barrickman, and Christine Wall of Duke University that found no relationship between relative brain size and group size in lemurs (a clade of strepsirrhine primates that last shared a common ancestor with the haplorhine monkeys and apes about 75 million years ago). However, where it comes to these more recently evolved haplorhines, the data is remarkably consistent with Dunbar’s interpretation (see Figure 1 below).

Primates, and humans in particular, are such good social cooperators because we can empathize with others and coordinate our activities to build consensus. It is what also makes us so remarkably deceitful, allowing us to manipulate other members of our group by intentionally making them think we will behave one way when our actual plans are quite different. A successful primate is therefore one who can keep track of these subtle details in behavior and anticipate their potential outcome.

But therein lies a chicken-and-egg problem. How do we know whether it’s the social networks that have promoted an increase in neocortical growth or whether that same expansion of gray matter simply allowed these social networks to expand? A new study published in the November 4th edition of Science addressed this question by housing monkeys in different sized groups to find out if their neocortical gray matter increased as the number of individuals grew. A team of neuroscientists led by Jérôme Sallet and Matthew Rushworth of the University of Oxford in England randomly assigned 34 rhesus macaques to separate social groups ranging in size from 1 to 7. The researchers conducted magnetic resonance imaging (MRI) scans on 23 of the monkey’s brain structures both before they were placed into their various groups and again after more than a year had passed.

Their analysis revealed a clear, linear relationship between the size of a monkey’s social network and an increase of neocortical gray matter in regions involved with social cognition (such as the mid-superior temporal sulcus, rostral prefrontal cortex as well as the frontal and temporal cortex). Previous research has shown that these regions are important for a variety of social behaviors, such as interpreting facial expressions or physical gestures, “theory of mind,” and predicting the behavior of other group members. Overall the monkeys demonstrated an expansion of gray matter ranging from 3-8% (depending on the brain region) for each additional member of their social network. In other words, monkeys that lived in the most socially complex group had an average increase of 20% more neocortical growth than monkeys housed individually.

Figure 2. Gray matter increased with social network size; P < 0.005. Reproduced from Sallet et al. (2011).

In order to make sure that the increased brain growth corresponded with more successful social behaviors, the research team also tested whether there was a correlation between gray matter volume and a monkey’’s rank within their group (as in many other primates, rank in rhesus macaques is a strong predictor of reproductive success). Once again the researchers found a linear relationship, at a ratio of 3-to-1, between a monkey’s dominance behavior and the growth of key regions in their neocortex. This means there was individual (potentially genetic) variation that allowed certain monkeys to experience greater neocortical growth than other group members that were living in an identical environment. This strongly suggests that it is the cognitive demands of a larger social network that has resulted in the growth of brain regions beneficial to social behavior in primates.

“Social network size, therefore, contributes to changes both in brain structure and function,” said Sallet. “Individual variation in brain anatomy should have implications for an individual’s success within the social group.” Crucially, these individual differences remained consistent for more than four months. Certain individuals happened to be better suited for dealing with the demands of larger social groups, but they had to first live in that environment before their natural abilities could emerge.

This raises a provocative question. Individual variation is the raw material on which natural selection operates. But in a rapidly changing environment — like in many human societies ever since the invention of agriculture 10,000 years ago — there will be many new adaptive opportunities that may never have existed throughout most of human evolution. Consider those individuals who have made successful careers (and had large families) through their skill as novelists, DJs, or computer programmers. Certain aspects of their skill sets would certainly have been based in our long history of hominin evolution, but other parts may have had little or no adaptive value at any other time than the present.

It is this capacity that was the focus of a study published last month in Proceedings of the Royal Society that investigated the biological variability in another form of social behavior: online social networking. In a collaboration between neuroscientists and anthropologists led by Ryota Kanai and Geraint Rees from the Institute of Cognitive Neuroscience at University College London, the researchers investigated social media users, specifically Facebook, for the same kinds of biological variation that distinguished certain social monkeys over others.

“These services allow individuals to articulate and make visible their friendship networks,” explained Kanai, “and it is apparent that there is considerable variability in the size of such networks.”

By comparing the differences between individuals and the size of their online network of friends, real-world friends, as well as the size of neocortical brain regions involved in social behavior, the researchers were able to identify a strong correlation between the volume of three neocortical regions and the number of that individual’s Facebook friends. Crucially, these brain regions (the right superior temporal sulcus, left middle temporal gyrus, and entorhinal cortex, areas previously implicated in social perception and associative memory) had no relationship to the real-world social networks of these individuals. There was only one area, the amygdala, that showed a correlation between gray matter density and both forms of social networking. The other brain regions seemed to be, quite literally, wired for the web.

However, unlike the study with monkey social networks, there was no way to determine whether it was the number of an individual’s Facebook friends that had pushed this neocortical growth or if it was actually the other way around. But given the similarities in function, it is certainly a tempting conclusion to reach. Could it be that online technology has allowed some individuals to express (and expand) a form of social behavior that emerged for other adaptive reasons but which has been underutilized until now?

Given the regular jeremiads from self-appointed cultural guardians over what they see as the danger of our increasing reliance on online networks at the expense of real-world ones, the possibility that we may actually be enhancing untapped potential is a refreshing idea. At the same time, however, it’s probably a good idea to wait until we know for sure before sharing the news with any other primates. The last thing I need is a slew of hairy faces crowding my wall. I have enough trouble keeping track of my online network of friends as it is.

References:

Sallet, J., Mars, R., Noonan, M., Andersson, J., O’Reilly, J., Jbabdi, S., Croxson, P., Jenkinson, M., Miller, K., & Rushworth, M. (2011). Social Network Size Affects Neural Circuits in Macaques, Science 334 (6056), 697-700. DOI: 10.1126/science.1210027

Kanai, R., Bahrami, B., Roylance, R. and Rees, G. (2011). Online Social Network Size is Reflected in Human Brain Structure, Proceedings of the Royal Society B: Biological Sciences, published online Oct. 12, 2011. DOI: 10.1098/rspb.2011.1959

Dunbar, R.I.M. and Shultz, S. (2007). Evolution in the Social Brain, Science 317 (5843), 1344-1347. DOI: 10.1126/science.1145463

MacLean, E.L., Barrickman, N.L., Johnson, E.M. and Wall, C.E. (2009). Sociality, Ecology, and Relative Brain Size in Lemurs, Journal of Human Evolution 56 (5), 471-478. DOI: 10.1016/j.jhevol.2008.12.005

Tambayong y Carley (2013): Análisis de red de textos en etnografía

Tambayong - Network Text Analysis in Computer-Intensive Rapid Ethnography Retrieval: An Example from Political Networks of Sudan