HumansPosted by David Sumpter Mon, March 01, 2010 10:11:53 This week's Economist has an interesting series of articles on the data explosion we have experienced the last few years. Quite alot of this explosion is related to human collective behaviour. As Mehdi pointed out in an earlier post, Google is leading the way here. But there are lots of other sources it seems that big businesses are very interesting in spotting patterns in collective behaviour.
Its funny reading an article like this because first I got the impression that there was lots we can learn from these companies. But later on I came to the conclusions that they just get massive datasets load them in to R and look for correlations between things. Some of the correlations they were apparently surprised by were pretty obvious really, e.g. people mass buy easy to cook food before a hurricane is going to strike. I'm not sure I can do better than this, but it seems the idea of dynamically modelling lies a long way off.
AnimalsPosted by David Sumpter Fri, February 26, 2010 05:43:02 I am a bit late reading this, but I have just read Edwards and Pratts paper on rational decision-making by Temnothorax ants. It seems to be a bit of a fashion just now to test whether groups are rational or not. The standard technique is to first give a studied organism a choice between two options A and B and establish their preference for these two options. After this a choice between A, B and a decoy C is given, the decoy being of lower quality than A or B and thus irrelevant to the rational decision-maker. It seems the individual animals and humans do change their frequency of choosing A and B dependent on the attributes of C, exhibiting irrationality. Stephen Pratt's house-hunting ants were however rational, exhibiting the same preference pattern when choosing between two nest sites in the presence and absence of decoys.
There is a suggestion that groups can be more rational than individuals because they maintain some level of independence. When moving to a new home, most of the ants do not see all of the options and are thus less likely to be influenced by decoy alternatives. The very reason that individuals are making irrational decisions is that they have access to too much information.
AnnouncementsPosted by David Sumpter Tue, February 02, 2010 09:33:43 Two postdoctoral positions are available in the Collective Behaviour Group, at the Centre for Statistical Mechanics and Complexity - CNR Rome. The positions are funded by the IIT project ART-SWARM, focusing on the experimental and theoretical study of collective behaviour in bird flocks and insect swarms, and its potential applications to artificial systems.
The candidates will work under the supervision of Irene Giardina and Andrea Cavagna. Information on our collective behaviour research can be found here.
AnnouncementsPosted by Audrey Dussutour Wed, January 27, 2010 14:54:09 Special Issue on Collective decision in biological swarms
Swarm Intelligence http://www.springer.com/11721
This special issue calls for papers focusing on different aspects and issues of collective decision in animal groups, exploring the problem in different animal models and focusing on different aspects of decision: what is the pooling function? by what mechanisms can informed individuals lead the group? what compromise is found in the trade-off for speed and accuracy? In summary, how do individuals within a group integrate information in order to reach consensus? and when does the group better split than reach a consensus?
Micro-organismsPosted by David Sumpter Fri, January 22, 2010 13:17:57 Atsushi Tero, Toshi Nakagaki and their colleagues have published a nice new paper about slime moulds solving optimisation problems. This time they have shown how they can design transport networks just as well as, if not better than, humans.
HumansPosted by David Sumpter Thu, January 07, 2010 17:53:55 Dirk Helbing has set up a webpage for something calledVISIONEER: Envisioning a Socio Economic Knowledge Collider. The idea is to collect together ideas which can shape future research of collective behaviour of humans. He is putting together a report for the EU on this theme, hopefully resulting in long term funding for this type of research.
I thought it was quite cool to use collective distributed intelligence to find the best way to study collective intelligence.
HumansPosted by Mehdi Moussaid Tue, December 08, 2009 19:08:26 Recently, Google has released two nice tools that could be used to observe nice patterns of humans activity. The first one is Google trends. It allows you to see how often a specific keyword has been searched on Google over time. One can easily observe some nice 'herding' phenomena where everybody is suddenly paying attention to one specific event. For example, the search curve for keyword 'Harry Potter' shows a sudden peak during summer 2007. By cumulating the search volume day after day, you find a nice S-shaped curve, typical from phase transitions. Here, the transition is from a state where nobody cares about Harry Potter to a state where most people have paid attention to it. The same kind of curves can be observed for keywords 'tsunami' in 2004 (with a sharper transition), or 'bejing' in 2008 and many others. I've been talking about that during the last ECCS conference (see here).
Similarly, I was surprised by the astonishing regularities of search patterns over years. Try to compare the curves for keywords such as 'snow' , 'beach' , 'football', or 'mothers day' , 'fathers day': Each year displays the exact same search pattern, same peaks , same slope... and even the same mistakes, such as a small amount of people searching for 'fathers day' during August... (See also the nice pattern for the keyword 'science').
The other tool is Google flu trends, which displays data about the flu epidemics over the world. Again, there are many interesting things to say and to observe, such as the regularities of the epidemics over years, the spreading of the flu among neighboring countries, or the great correlations between these curves and the search volume for the keyword 'flu' each year... Therefore, it's not a surprise that a team from Google Inc. has made a Nature paper out of it: Detecting influenza epidemics using search engine query data
For sure, there's a lot to learn just by observing the web.
I was particularly struck by some work by Kent Hill from UCLA on extremely coordinated collective behavior in African Trypanosomes. These parasites are responsible for sleeping sickness. They have a paper in press in PLoS Pathogens so I won't say more for now, but it's one to look out for. The degree of coordination is quite remarkable and provides new concepts for the development and pathogenesis of parasitic protozoa. Of course the immune response to such parasites is collective itself, and that too is poorly understood.
