March 26, 2010
Playing the Lemonade Game: Metacognition in Game Simulations.
A few details about our work on the Lemonade Stand Game leading up to our entry in the Lemonade competition at the end of 2009 can be found in our latest paper, presented at this weeks Behavior Representation in Modeling & Simulation conference. The competition was a tournament between agents, playing out many strategies that all tries to succeed to win lemonade market share on the beaches of a fantasy island.
Abstract: The Lemonade Game is a three-player game in which players have to pick locations on a circular board, which are as far away as possible from those chosen independently by other players. Players may observe other player's moves and infer their strategies. The game was studied using a competition of cognitively motivated agents, which inherit properties of adaptivity and stochasticity from human memory and decision-making, and simplistic, yet effective agents implementing fixed strategies. We argue that metacognition is the unique attribute that allows sophisticated agents to adapt to unforeseen conditions, cooperators and competitors.
D. Reitter, I. Juvina, A. Stocco, and C. Lebiere. Resistance is futile: Winning lemonade market share through metacognitive reasoning in a three-agent cooperative game. In Proceedings of the 19th Behavior Representation in Modeling & Simulation (BRIMS), Charleston, SC, 2010.
Metacognition was also explored in my cognitive model submitted to the Dynamic Stocks&Flows Competition last year. There, the model did just what I think human participants in a psychological experiment did: try different strategies to solve a problem, and pick the one that performed best most recently. Weighing recency and frequency of experiences or pieces of knowledge is a common theme in such models; more research is needed to find out how exactly people combine their experiences to make (mostly) good decisions. The model won the first prize in the challenge. Still, the model does not explain enough of the variance observed in the empirical data. A look back to determine what we have learned from the DSF challenge was presented in a panel discussion at this year's Behavior Representation in Modeling & Simulation conference.
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January 8, 2010
US Airways
This winter's itinerary: Pittburgh-Charlotte,NC-Frankfurt,Germany, and Munich,Philly-PA,Pittsburgh, at a whopping $900+ price tag. Results: Not flying with US Airways again if I can avoid it.
My First flight was cancelled due to some software problem with an onboard computer on their Embraer jet, after we've been on board for an hour. Rerouted - next flight 4 hours late due to a failed hydraulic pump. Then a fully booked overnight flight in the wrong kind of seat. Arrival: 7 hours late on the other side of the Atlantic in the end, no compensation from US (only EU airlines are required to reimburse/make happy their customers). I've learned a lesson about redundancy: when you fly aircraft that have 12 hydraulic pumps (not all redundant), you don't just increase safety while in the air - you also increase the likelihood that the aircraft is going to be grounded because one of them fails. (Note to self: compile list of airlines that charge for infants.)
Return flight: East Coast in the winter chaos; plane running one hour late as it is being de-iced. Is ice in January such a surprise that this couldn't have been anticipated? No more US Airways flying for me. It does not suffice that their cabin staff has always been super-friendly, and that they have a pilot who can fly very big gliders on staff. The getting-me-there-on-time bit has to work. Rant finished.
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December 17, 2009
Building small, big and fast aircraft: The power of startups
Just saw a video (see below) of the newly-built SpaceShipTwo aircraft, a plane that will take a small number of super well-off to the end of the universe as we know it, or just above the atmosphere, to be precise. It's a fascinating design, but what's much more fascinating is the enterpreneurship story behind this.
Since 2004, two small companies managed to develop two spacecraft and two carrier aircraft (jets); the first combination winning the 10M$ X-Prize in 2005, the second in the process of achieving FAA approval.
Second, take the gliders (sailplanes) that I enjoy flying. All of them are developed and built at affordable prizes by small companies such as the German companies Grob, Schempp-Hirth, or Schleicher. They are built to withstand much higher G-forces than those airliners and reach amazing efficiency and high speeds. (Great powered aircraft are similarly built by small and medium-size aviation companies such as the American Cirrus.)
Those gliders have been made from composite materials (fiberglass+gel coat) since the late 70's. I'm just mentioning this because I'm now introducing the herculanean efforts building the Boeing 787, the first composite airliner, taking the dedication of thousands of engineers and mechanics over a decade to build. The Airbus A380, the world's largest airliner, wasn't different.
Of course, the comparison is ridiculous, even in the case of the pressurized, jet-propelled space craft+carrier planes that fly faster and higher than airliners, and that are built to comparable safety standards. Is the technical challenge that different when scaling up a pressurized jet from a dozen to a few hundred passengers?
It seems clear: aircraft development doesn't scale well. I bet that very similar cases can be made for software development - compare the behemoth that is Windows (maintained by thousands of programmers at Micrsoft) to the Mac operating system that was initially developed by far fewer people at NeXT. Why is that so? It's a fascinating and unanswered question from the point of view of research into emerging collaboration in teams and of communication networks to explain the apparent loss in efficiency.
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December 9, 2009
Are we better off without religion?
Christmas is coming up, and just in time the Guardian goes over some recent research in the social sciences asking the question: are we better off without religion?
Sociologist Gregory Paul's view is that religion is a sign of dysfunctional societies. Generally, societies with higher "popular religiosity" also fare worse when it comes to measures of community success, such as the number of jailed people, sexually transmitted diseases, corruption, and the like (Paul, 2005, 2009). The causality of this is not clear, but Paul argues that religiosity is the result rather than the cause. One should note that such correlations depend on a subjective, albeit wide-ranging Successful Societies Scale: if socio-economic factors would be weighted heavily, the most-religious country (US) would end up close to the the least-zealous societies (Sweden, Japan).
One may wonder how much of the originally intended "good" is left in the world's religions - the good that stabilized societies through more or less arbitrary rule systems. The good that kept people healthy ("no pork!") and made communities stronger ("Love thy neighbor!"). The good that allowed some preachers and some movements out of many to evolve and develop into world religions. Note Pope Benedict II's (Joseph Ratzinger's) views on liturgy, which argue that the "new" forms have made church-goers self-indulgent and ignorant of views from outside (the priest turning to the congregation, preaching in their language - his conclusion: back to the Latin mass, is, of course, ridiculous).
Christmas traditions are a good example of a combination of religious and pagan traditions that have lost their meanings. I for one am glad to avoid Santa Clauses, Christmas shopping in stores, and I greatly enjoyed my department's "non-denominational Holiday party".
Paul, Gregory S., Cross-national correlations of quantifiable societal health with popular religiosity and secularism in the prosperous democracies: a first look. Journal of Religion & Society. 7, 2005.
Paul, Gregory S., The Chronic Dependence of Popular Religiosity upon Dysfunctional Psychosociological Conditions. Evolutionary Psychology 7(3). 2009.
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August 16, 2009
Improvised Explosives in Iraq: Of makers, disarmers, and the dead.
The Hurt Locker is a film about a US bomb squad dying and cheating death in the heat and dust of Iraq. It is fiction, shot and edited in documentary style. Creepy Realism. Coming out of the movie I am still wondering: why did the US decide to send soldiers to hell, and how could the US-UK coalition commit the arson that removed a dictatorship to create the Iraqi hell in the first place? Questions, not new. The Hurt Locker is out in US theaters now. It's worth seeing.
This week, the New York Times ran a remarkable piece titled How Baida Wanted to Die about a Iraqi suicide bomber who did not manage to explode her bomb. It is wide-spread religion that brainwashed a young woman. But the horrors of war and her marriage triggered her decision to join those who carry their belt stuffed with explosives to a busy market. A police officer told the reporter before her interview with the young woman: "You're going to like Baida".
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