Archive for October, 2010

foursquare was down

Thursday, October 21st, 2010

salvo told me that  foursquare had one of

its databases overloaded with check-ins and consequently experienced a downtime of 11 hours! so central services are unscalable (unreliable) and they need to be decentralized. partial decentralization is the solution in the industry, and full decentralization still remains in the academic circles ($$ reasons). few years ago, i asked the question: what if mobile social-networking services were to be decentralized. it was an academic exercise that resulted in:

social activism and weak ties

Tuesday, October 19th, 2010

In The New Yorker, Malcom Gladwell argued that online social networks such as Twitter aren’t good for “real” social activism, not least because they support only weak ties. The assumption here is that social activism needs strong ties. In reality, the opposite is true. Mark Granovetter’s classic 1973 paper titled “The Strength of Weak Ties” discussed the relationship between tie strength and social activism. Granovetter considered the redevelopment project of the Italian neighbourhood in Boston in the 60s. The project was widely opposed by the community but went forward. Why? The problem was the absence of weak ties within the Italian neighbourhood. Social life revolved around members and unchanging groups of friends, and the density of strong ties (but relative lack of weak ones)  inhibited any political change. Gladwell cited Granovetter’s article but didn’t read it. Gladwell titled his article “Why the revolution will not be tweeted”. Perhaps revolution is not what we need. We might just need people who read what they cite and don’t fall into the trap of “the old dismissing the new” (substitute “telephone” for “twitter”/”facebook” and see how the article reads).#fail

serious games

Tuesday, October 19th, 2010

meeting at nesta about how serious tasks are being made more game-like. example of serious games: Tate TrumpsRe-mission (helps teenagers with cancer), SuperMe (teaches how to cope with obstacles in life),  Quest to Learn (the school in New York organised around game principles), The Good Gym (connected people who want to get fit with

older people who need visitors. More on the meeting (write-up). More on serious games ( ‘Games Lessons’ from The Economist).

Rethinking Mobile Recommendations…

Wednesday, October 13th, 2010

…Is it time to forget ‘nearby events’ and look at neighbourhoods?

Location-based services that emphasise recommending nearby events are doomed to failure. Here is why (more on this paper). We have recently studied the relationship between preferences for social events and geography in the large metropolitan area of Greater Boston. We sampled location estimations of one million mobile phone users in the area, combined the sample with social events in the same area, and inferred the social events attended by 2,519 residents. Upon this data, we tested six simple algorithms for recommending social events and found a couple of extremely interesting things:

  • The most effective algorithm recommends events that are popular among residents of an area.
  • The least effective, instead, recommends events that are geographically close to the area.

Conclusion: When we build and deploy new technologies in our cities, we should go back to what Jane Jacobs taught us about neighbourhoods.

Companies that fail to do that are doomed to failure. For more, here is the paper, which I’ll present at ICDM.

Call to action: We would be very happy to collaborate with mobile social-networking companies. My email:


lbs in uk/europe

Monday, October 11th, 2010

i was compiling a list of location-based service companies in uk/europe. now i decided to “crowdsource” it :) do you know any company in this area? please comment below! i’ll start with …

1. rummble

simmelian ties in organizations

Wednesday, October 6th, 2010

today Prof David Krackhardt (CMU)  gave a very very nice talk titled “Simmelian Ties in Organizations “. david krackhardt greatly contributed to the discipline of cognitive social networks and has extensively studied the power of simmelian ties in organizations (his bio). here is the result of my live blogging during his talk:


Web Science: A Royal Society Meeting (day 2)

Tuesday, October 5th, 2010

following this post, notes for day 2. featured:  luis von ahn, jonathan zittrain, nourish contractor, and manuel castells.