In 2010 over the course of seven weeks 253 million Facebook users became part of an experiment to determine how people diffuse information among their social groups. The study was done by Eytan Bakshy who at the time was working on getting his Ph.D. in Information from the University of Michigan. At the time of the study there were 500 million users of Facebook, so this study involved over half of the Facebook population.
Facebook normally uses an algorithm that they call EdgeRank in order to determine what appears in a users news feed by analyzing which connections are most important to you and which kinds of content should appear higher than others. In the experiment done by Bakshy he created two groups of people. In the first group if a friend posted a link they saw it in their feed. In the second group if a friend posted a link the link was randomly censored and would not appear for members of the second group. They were not however blocked from posting the same link themselves.
Group Two Example:
- Friend A posts a link
- Person inside of Group 2 would randomly have the link Friend A posted blocked
The experiment analyzed how closely tied the user was to those in their friends list. They measured the strength of the tie by measuring four types of interactions:
- Frequency of private online communication between the users in the form of Facebook Messages
- Frequency of public online interaction in the form of comments to posts
- Frequency of real world coincidences in terms of being labeled as appearing in the same photograph
- Frequency of users responding to the same Facebook post with a comment.
They analyzed the data for three months prior to the experiment.
The study found when users were exposed to a link they were more likely to spread the link faster than the users that were not exposed to the link on their feed. The stronger a connection to someone, or a group, the more likely we are to share the link they posted on our own wall. The weaker the connection the less likely we are to share a link, however we still will share links that are “novel”. They state, “This suggests that weak ties may play a more dominant role in the dissemination of information online than currently believed.”
At no time in the study, or article, does it indicate that informed consent of the 253 million users was received in order to have this study done. Facebooks privacy statement about how they use the information users post to their accounts is a bit vague on the issue. It does state though that we do consent to Facebook using the information by using and posting information to their site.
The entire study was done with the consent of Facebook. In an interview with Bakshy he told the interviewer “that he has “a good amount of freedom” at Facebook to research whatever he wants to look into about the social network and no one tells him what to investigate and what to leave alone.”
Links in Article:
[i] The Role of Social Networks in Information Diffusion (http://arxiv.org/abs/1201.4145)
[ii] The End of the Echo Chamber (http://www.slate.com/articles/technology/technology/2012/01/online_echo_chambers_a_study_of_250_million_facebook_users_reveals_the_web_isn_t_as_polarized_as_we_thought_.html)
[iii] University of Michigan Personal page of E. Bakshy (http://www-personal.umich.edu/~ebakshy/)
[iv] The Ultimate guide to the Facebook Edgerank Algorithm (http://econsultancy.com/us/blog/7885-edgerank-the-most-important-algorithm-you-ve-never-heard-of)
[v] The role of social networks in information diffusion (http://arxiv.org/pdf/1201.4145v1.pdf)
[vi] The role of social networks in information diffusion Pg. 10 (http://arxiv.org/pdf/1201.4145v1.pdf)
[vii] The role of social networks in information diffusion Pg. 1 (http://arxiv.org/pdf/1201.4145v1.pdf)
[viii] The role of social networks in information diffusion (http://arxiv.org/pdf/1201.4145v1.pdf)
[ix] The End of the Echo Chamber Page 2 (http://www.slate.com/articles/technology/technology/2012/01/online_echo_chambers_a_study_of_250_million_facebook_users_reveals_the_web_isn_t_as_polarized_as_we_thought_.html)
[x] Facebook Privacy Statement How We Use the Information We Receive (http://www.facebook.com/about/privacy/your-info#howweuse)
[xi] The End of the Echo Chamber Page 2 (http://www.slate.com/articles/technology/technology/2012/01/online_echo_chambers_a_study_of_250_million_facebook_users_reveals_the_web_isn_t_as_polarized_as_we_thought_.html)
[xii] The End of the Echo Chamber (http://www.slate.com/articles/technology/technology/2012/01/online_echo_chambers_a_study_of_250_million_facebook_users_reveals_the_web_isn_t_as_polarized_as_we_thought_.html)
[xiii] Facebook Data Team (http://www.facebook.com/data)