Showing posts with label Network. Show all posts
Showing posts with label Network. Show all posts

Sunday, January 30, 2011

SIS model at Harvard

I thought you might be interested in two articles from a research group at Harvard. This group has adapted the susceptible–infected–susceptible (SIS) model, which has traditionally been used to study infectious disease, for use in studying social contagions. SIS was originally developed to model infectious diseases that do not confer immunity (such as many sexually transmitted diseases). The group modified the SIS model to make it more appropriate for studying social contagions by including the possibility for ‘automatic’ (or ‘spontaneous’) non-social infection (SISa). A key feature of the SISa model is its ability to characterize the relative importance of social vs non-social transmission by quantitatively comparing rates of spontaneous versus contagious infection.  The authors illustrate with two social contagions – emotions and obesity.

The first article applies SISa to obesity data (published this week in PLoS Computational Biology).  The model forecasts further increases in the obesity epidemic, topping out at around 42%. The second article is from July 2010 and to study the flow of emotion through large social networks. Both employ data from the Framingham Heart Study.

This work was funded in part by NIH.

Infectious Disease Modeling of Social Contagion in Networks.

Hill AL, Rand DG, Nowak MA, Christakis NA, 2010 

PLoS Comput Biol 6(11): e1000968. doi:10.1371/journal.pcbi.1000968

http://www.ploscompbiol.org/article/info%3Adoi%2F10.1371%2Fjournal.pcbi.1000968

http://www.sciencedaily.com/releases/2010/11/101104171346.htm

Emotions as infectious diseases in a large social network: the SISa model

Alison L. Hill, David G. Rand, Martin A. Nowak, Nicholas A. Christakis

Proceedings of the Royal Society B  - Biological Sciences

Published online before print July 7, 2010, doi:10.1098/rspb.2010.1217

http://rspb.royalsocietypublishing.org/content/early/2010/07/03/rspb.2010.1217.full.html

http://www.wired.com/wiredscience/2010/07/contagious-emotions/

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Monday, September 27, 2010

Network effects are not predetermined

작년 재작년경에 있었던 Malcolm Gladwell과 Duncan Watts간의 논쟁 (see http://bit.ly/9iVCqg and http://bit.ly/bRuwc4)을 떠올리게 하는 기사.


Network가 health나 기타 여러 분야에 있어 가지는 contagion effect라는 것은
일정하게 나타나는 것도 아니고, context과 messenger에 따라 달라질 수 있다는 것...

...The mixed findings suggest to Valente, who's done some of the leading work on network-based health interventions, that programs may need different designs based on the type of social network they're intended to help. This important point, he adds, has been entirely ignored in all work on health promotion.

"You can't divorce the content of the program from the people delivering it," he says. "The message is really the messenger."


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이와 관련해서... 정말 Christakis와 Fowler의 연구가 viral하게 퍼져나갔다.
NYT에도 소개:
Damon Centola의 연구까지도 소개....

이런 연구들이 '학계'내에서 얼마나 serious하게 받아들여지는지는 사실 토론의
대상이 되겠지만, 연구의 대중성이 가지는 힘이란 참 대단하다는 것이 느껴진다.
(Sandel의 Justice처럼)