Friday, March 30, 2007

Some new papers from our group

Jarbas Silva and A. Linhares, "Cognitive reflection: the ‘premature temperature convergence’ hypothesis", accepted in the proceedings of CogSci2007, Nashville, USA.

Abstract. We present a new hypothesis concerning cognitive reflection and the relationship between System 1 and System 2, corresponding roughly to intuition and reason. This hypothesis postulates a tighter integration between systems than is implied by the common framework of separate modules. If systems are tightly coupled, as we propose here, an explanation of cognitive reflection may rest in the premature convergence of an ‘entropy’, or ‘temperature’, parameter.


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Linhares, A. & Winter, C. (2007) "Internet search mechanisms and distortions of the semantic space: The scientific challenges facing the Googles", accepted at Data Mining & Information Engineering 2007, New Forest, U.K.

Abstract. Ever since the launch of Altavista, internet search engines have become a multi-billion dollar industry, with fierce competition between Google and the three major competitors. One of the challenges involved is to rank search results in a way that places the most meaningful results at the top. In order to do this, the algorithms involved must try to grasp the actual meaning, the semantics, embedded in a search query. In this paper we discuss a problem we call "distortions of semantic space". Distortions of semantic space occur regularly in people's texts, writing styles, labeling of images, etc. We present a number of examples of distortions of semantic space, and analyze the problem. We also comment on new computational architectures that have tried to handle this problem, albeit the state of the art still remains far from the needed challenge.


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Linhares, A., (2007) Free will and the power of veto: convergent evidence from decision-making. Accepted in EuroCogSci, the European Conference of the Cognitive Sciences, Delphi, Greece.

Abstract. There is immense controversy over Libet’s “power of veto” interpretation of free will. This theory states that humans have free will by an indirect way: by the ability to discard, or veto, actions that are automatically provided by one’s brain (independently of one’s conscious thought or will). Libet’s theory stems from powerful, robust, experiments, which show that one’s brain prepares for an action before one is conscious of the action. These experiments have been robustly replicated, so there is not much to argue scientifically, besides its interpretations and the philosophical implications for free will. In this article, we present convergent evidence to the “power of veto” doctrine. Surprisingly, this convergent evidence arises from a field which has hitherto ignored Libet’s findings: the field of decision-making.


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Linhares, A., and Brum, P., (2007) Understanding our understanding of strategic scenarios: what role do chunks play? Accepted for publication, Cognitive Science, 28p.

Abstract. There is a crucial debate concerning the nature of chess chunks: one current possibility states that chunks are built by encoding particular combinations of pieces­on­squares (POS); and that chunks are formed mostly by “close” pieces (in a “Euclidean” sense). A complementary hypothesis is that chunks are encoded by abstract, semantic information. In this paper we extend recent experiments and show that chess players are able to perceive strong similarity between very different positions if the pieces retain the same abstract roles in both of them. This casts doubt on the idea that piece­on­square information is the key information encoded in chess chunks, and we propose instead that the key encoding involves the abstract roles that pieces (and sets of pieces) play—a theoretical standpoint in line with the research program in semantics that places analogy at the core of cognition.

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Friday, March 16, 2007

Donnelly on statistical intuitions

Peter Donnelly comments on some of our terrible failings in statistical intuitions. Hilarious talk, serious stuff.

Sunday, March 11, 2007

Thanks to my students

Thanks, folks, for the honor. God knows if I deserve it. This year we haven't had a proper videoconference from the US, but it was really great to see you crazies in person. Go out into the world, my children, and make buckloads of money!

Then hire me!

Yours, always... --A.

Thank you, Doug

It has been my pleasure and priviledge.

Wednesday, March 7, 2007

Maybe this will work.

>From The Onion:

NEW YORK—With the Dow Jones Industrial Average dipping below 12,200 at lunchtime today, floor trader Michael Campos, 24, is making an extraordinary personal effort to bring the index over the top before the closing bell later this afternoon.

Enlarge Image Brash Young R

Campos leads an impromptu wave in hopes of getting telecommunications giant AT&T's stock price up.

"C'mon, show some pride out there for God's sake," Campos said from the floor of the New York Stock Exchange. "What the hell is wrong with you? Hey, Johnson & Johnson, put a little heart into it!"

Though the Dow Jones, comprising 30 of the largest and most widely held public companies in the United States, fluctuates based on external market forces such as supply and demand, Campos said the Dow can overcome any obstacle if it "just shows the will and determination" to do so.

"Forget those rumors that OPEC will cut production by 1 million barrels a day, and just remember that what matters is what's in here," Campos said, pounding an open palm against his chest. "This is crunch time. Now let's show those chumps why we're the number one stock-market index in the world."

"That's what I'm talking about!" Campos added with a fist pump after seeing Proctor and Gamble Co.'s value jump a half point. "P&G's got the fire. How about the rest of you, huh? Where's the energy? You all have to be hitting on all cylinders, not just one or two of you."

"Don't get down, do not get down," he added. "Plenty of time left. Plenty of time."

Despite Campos' insistence that the Dow just needs a little boost before the closing bell to regain some much-needed confidence, Solomon Smith Barney financial analyst Troy McGrory said a late-afternoon rally was unlikely.

"With several technology companies failing to live up to forecast projections, and the Labor Department reporting a larger than expected jump in core wholesale inflation, it's shaping up to be a tough day for the index," he said. "I don't see how the Dow can pull itself out of this kind of slump."

But Campos, a recent graduate of McMaster University's Degroote School of Business, said he doesn't want to hear excuses.


Tuesday, March 6, 2007

Bias in the Emergency Room

From The Economist:

Signs of the times

Feb 22nd 2007 | SAN FRANCISCO
From The Economist print edition
Why so much medical research is rot

PEOPLE born under the astrological sign of Leo are 15% more likely to be admitted to hospital with gastric bleeding than those born under the other 11 signs. Sagittarians are 38% more likely than others to land up there because of a broken arm. Those are the conclusions that many medical researchers would be forced to make from a set of data presented to the American Association for the Advancement of Science by Peter Austin of the Institute for Clinical Evaluative Sciences in Toronto. At least, they would be forced to draw them if they applied the lax statistical methods of their own work to the records of hospital admissions in Ontario, Canada, used by Dr Austin.


How likely is a certain disease to be found above chance, given a certain condition? The basic logic is that, if you test 20 hypothesis individually, with a 5% threshold, one in 20 will, of course, be found to be "above chance". So there you have it: a huge load of hoax reports, duly stamped out in the best medicine journals, with sheer superstitious evidence. Dr Peter Austin really deserves merit for what he did.

Journalists will be sad to know about this one. Less chance for that nice front-page report:

"Doctors reporting increased risk of severe cancer for feeding the monkeys at the zoo."

Monday, March 5, 2007

Bias in the classroom, part (iii): The Beatles

The Beatles - I Want To Hold Your Hand Lyrics

Oh yeah, I'll tell you something,
I think you'll understand.
When I'll say that something
I want to hold your hand,
I want to hold your hand,
I want to hold your hand.

This is one view of university education. The textbook one. You have an unbiased textbook, which brings the truth to the masses, a professor who must hold a student's hand for them to actually learn anything, and students that need to follow the textbook and the professors' explanation, in order to learn stuff.

It may suit community colleges quite well. Students get trained to do some repetitive job.

But it's not for research universities. Students don't learn to think. They don't learn that every single text is bound with bias, limitations, useless information, and loads of crap errors, not to mention outdated. Worst of all, since every single person on this planet is convinced that they really think, they never learned that it is actually a real effort to think through issues. It's like Descartes used to say: "everyone thinks that they have maximum common sense, when related to others". In this view of the system the analogies are: profs are like tutoring guides, holding the hands of students, which are like customers, getting "served". I think you'll understand...

A friend of mine was just telling me the other day (she's a sharp mathematician with a great PhD thesis, but works in a place more like a community college instead of a proper research university):

The problem with using a (particularly famous) textbook is that, when I point out the errors and shortcomings to students, they side with the book! They'd rather take the authority of a printed document than actually going through the damn sweaty process of thinking through an issue and perceiving that, regardless of its prestige, a book is as faulty as a good wikipedia entry such as this or this or this or this or this or this or this.


How can you reply to that?
Oh yeah, I'll tell you something,
I think you'll understand.
When I'll say that something
I want to hold your haaaaand,
I want to hold your haaaaaaaaaaaaand,
I want to hold your hand!

Sunday, March 4, 2007

On the consciousness test

Here's Aeolist on the "consciousness" test:

People tended to rate the toddler as more conscious than the corporate executive, and to rate Google as more conscious than the robot. I can understand the former, even if I disagree with it, but the latter is just puzzling. Perhaps it comes about from the way we talk and think about firms as though they were conscious actors? But don’t we think about robots that way just as often? Perhaps when we think of robots, their wholly mechanistic character is more salient, whereas firms have a less intimate association with mechanism.
Well, the way Google was presented was, to me at least, quite "conscious" (or perhaps I should say quite self-controlled, since that's the test I did). (Of course I fully agree that it is preposterous to say that the toddler is more conscious than the corporate guy. People seem to be "punishing" him for his greed, I guess.)

Back to Google vs the robot. I had studied Kismet some years ago and to say that it has any understanding or "empathy" is to fall for the Eliza effect. The same thing happens to Google, the search engine. However, in the description of Google I had, it mentioned the company, headquartered in California, with 9400 employees, and so on. So even if I think the search engine does not exercise any self control whatsoever, I think it is fitting to say that the company does.

The real issue I see here is: can we ascribe psychological terms to companies? (or to other agglomerations of psycho-beings?)

First, in a realpolitik sense, we should ask: can we not? Because analogy and metaphor pervades our language and concepts and thinking, can we not think that Google is worried about privacy, lawsuits, etc? We are bound to think in these terms. It's just not something that we'd have a choice, I guess.

But is Google really worried about Microsoft, in the same sense that people are worried about weight loss? Is the United States really worried about Iraq? Is it becoming consciously concerned with global warming? Is it fitting to apply psychological terminology to aggregations of people? Would there be a real psychological phenomena in there?

My first take would be 'no'--there is no collective mind, and those are metaphorical uses. Yet, as we understand more and more about cognitive processing, the resemblances between a person's thinking (a "real" psychological event) and a group's (a "metaphorical" one) seem to be enormously striking. But that's just my first intuition; I can't spell out the argument precisely. Maybe later.

Me, and the average responder

First, check this out. I went for the 'self-control' survey. Results:

How the average person ranked the characters:
  1. Greg Nicol
  2. Jill Hannon
  3. John Griffin
  4. Kathy Robinson
  5. God
  6. Google
  7. Lucas Dobson
  8. Rebekah Malin
  9. heron
  10. kismet
  11. chicken
  12. The Mona Lisa
  13. rock

How you ranked the characters:
  1. Google
  2. John Griffin
  3. =Greg Nicol
  4. Jill Hannon
  5. Kathy Robinson
  6. Rebekah Malin
  7. Lucas Dobson
  8. heron
  9. chicken
  10. rock
  11. =kismet
  12. =The Mona Lisa
  13. =God

The major blunder in cognitive science, perhaps ever?

COGNITIVE PSYCHOLOGY 4, 55-61 (1973)

PERCEPTION IN CHESS

WILLIAM G. CHASE AND HERBERT A. SIMON
Carnegie-Mellon University

This paper develops a technique for isolating and studying the perceptual structures that chess players perceive. Three chess players of varying strength - from master to novice - were confronted with two tasks: ( 1) A perception task, where the player reproduces a chess position in plain view, and (2) de Groot’s (1965) short-term recall task, where the player reproduces a chess position after viewing it for 5 sec. The successive glances at the position in the perceptual task and long pauses in tbe memory task were used to segment the structures in the reconstruction protocol. The size and nature of these structures were then analyzed as a function of chess skill.

This study is legendary and has created whole fields, such as "situation awareness", in which you investigate whether experts (say, a jet pilot) are aware of the situation they're in (by, for instance, suddenly blanking out all instruments).

I think this study is, quite bluntly, a non-sequitur.

But hey, this is Chase and Simon 73, and who am I to say that without presenting evidence?

Step forward Mr. Brum!

Bias in the classroom, part ii: the nature of the Monkeygon

Hofstadter walks into the euclidean geometry seminar for a new session:

"In today's session we will study the nature of the monkeygon. The monkeygon is a special polygon holding the property that it looks like a monkey. We will study many properties and functions related to the monkeygon, such as

  • the mini-monkeygon: the monkeygon with the smallest number of line segments
  • c(X), the maximum number of non-overlapping circles that can fit inside a monkeygon X
  • the perfect-monkeygon: the monkeygon X with smallest c(X) among all possible monkeygons
with those basic concepts properly established, we will then be able to move on to more advanced topics, such as the monkeyplex or monkeyhedra".
After an hour's study of the monkeygon, Hofstadter pulls out the rabbit from the hat, and everything starts to make sense.

Can you guess what this session is all about?

Hooray! The end of the world hath arriveth, finally! Hip hip...

About time now.

China dropped 9%, others followed suit; Greenspan is seeing nasty clouds up there in the sky, and I can't help but rejoice in watching the world fall apart.

Maybe I should rewind the tape a little.

If you want to understand Brazil, you must try to visualize 3 things:

First, the world's greatest natural resources on a gargantuan piece of land larger then the continental USA, properly packed with 180M people around the edges. Second, take out 90% of the brainpower you imagined in those 180M people. Finally, take out another 90% of the brainpower that's left in your imagination. Now you have a pretty good idea.

For these last few years, we have seen political scandals of the highest order. ALL top-ranking officials have been caught with their pants down (one, in fact, had 100K dollars in his underwear). Yet, despite the tragicomic corruption scandals, Lula, the Messiah, was re-elected. In the process the Messiah created a large divide in the country, throwing his own sins into "the elite". That elite, of course, was based mostly of poorly paid journalists pointing out that it is wrong to steal.

In any case, the economy saved the day for the "president". A strong currency pinned down inflation and increased gross earnings for the masses. Brazilian analysts heralded the economy's strenghts based on macroeconomic figures; inflation, exports, reserves, and so on. There is enormous consensus that Brazil is about to become investment grade just around the corner. The São Paulo Stock market has been on bullish for years, beating record after record. Since I have been bearish for quite some time now, it will be time to rejoice when the house of cards starts falling apart.

Lula the Messiah has never been in a financial crisis. His government is full of pathetic, embarassingly incompetent people such as the foreign policy or the economic ministers. In his first term, he managed to hire some 40 thousand additional government supporters employees, boosting government spending. Never in his entire life has he given any thought to the concept called productivity. The obvious result is Brazil's ridiculous rate of growth. Now, quite pathetically, he managed to create a fantasy dream "acceleration growth program", which will either fail fantastically or create a chicken's flight. He could very well buy some rapid growth now at the expense of tomorrow. He knows a lot about buying: this is, after all, the man whose presidency is under the charge of buying votes in congress for 30K reais/month.

But now that the storm may be finally coming we will stop seeing these ridiculous pretensions of greatness. Some think that the dollars flowing in were from exports... that view ignores the gigantic liquidity in economic markets, and the carry trade that Brazil had been receiving:

"The carry trade of Brazil is certainly one of the biggest in emerging markets and some people are reducing positions."


The party is about to stop anytime now. Expect to see that carry trade stop. Expect to see a higher dollar, inflationary pressures, stock market crashes, company crashes, the works.

Reality is knocking at the door.