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Fixing Steam's User Rating Charts

PacoSuarez A much simpler method (93 comments)

If the only two choices are positive/negative (or thumbs up/thumbs down or some other equivalent 0/1 scheme), here's a formula that should work fairly well:

(n_positive + 1) / (n_positive + n_negative + 2)

So a single positive review gives you a score of .6667, and a single negative review gives you .3333. For large numbers of reviews, the score quickly converges to the actual fraction. If you don't have any reviews, you are at .5000.

The mathematical justification for this formula is that if you try to use a Bayesian approach to estimating the true probability of getting a positive review, and you start with a flat prior, this formula gives you the average of the posterior probability after observing the given number of positive and negative reviews. The full posterior distribution is a beta distribution with parameters alpha=n_positive+1 and beta=n_negative+1.

This formula is often used when applying Monte Carlo techniques to the game of go. I believe a lot of programmers simply start the counters of wins and losses at 1 to avoid corner cases (like division by 0), and they accidentally use the correct formula.

about two weeks ago

Is "Scorpion" Really a Genius?

PacoSuarez Re:IQ of 197? (391 comments)

You forgot to divide by sqrt(2) in your erfc expression. The actual probability of IQ of a random human being over 197 is about 5e-11, which means about 0.35 humans should have it.

about 2 months ago

Exploiting Wildcards On Linux/Unix

PacoSuarez Re:Question... -- ? (215 comments)

While that is indeed the solution, it is also true that it is too easy to forget. Perhaps one could modify all commands to require the use of the "--" separator, or to warn if it's not present, at least if some environment variable is set. That could be very helpful for people trying to write more secure code.

about 4 months ago

The Billionaires Privatizing American Science

PacoSuarez Re:Good! (279 comments)

Please compare the supermarket shelves in the USA with those in Venezuela or North Korea and then come back here and tell me why big government controlling the means and distribution of production is a good idea, compared to the free market, with people providing each other with services in return for a token of exchange (currency).

I'm not saying that there isn't an element of truth in what you are saying, but you have to pick comparable countries or the comparison will mean nothing. So looking at North Korea versus South Korea is fine, as is comparing Venezuela to Colombia, or Cuba to Dominican Republic. If you want to compare the U.S. to anyone, perhaps Sweden would do. But Sweden is pretty darn nice. :)

about 7 months ago

Why Robots Will Not Be Smarter Than Humans By 2029

PacoSuarez Re:15 years? Try 200. (294 comments)

This idea that in order to achieve intelligence you need to understand how the brain works is preposterous.

We don't understand how grandmasters play chess, and yet we can build machines that play chess better than any grandmaster. The same thing will happen with more and more skills, and we'll get to a point where it will be clear that machines are more intelligent than humans.

2029 sounds optimistic to me, but the arguments in TFA are very weak:
* "What exactly does as-smart-as-humans mean?" It means "as good as humans at most tasks". The precise definitions won't matter when you actually see the machine in action.
* "Human intelligence is embodied." But artificial intelligence need not be embodied. If we can make a machine as smart as Stephen Hawking, I think we have done OK. I don't think his embodiment is a key part of his intelligence.
* "As-smart-as-humans probably doesn’t mean as-smart-as newborn babies, or even two year old infants." Of course not, but there is no reason a machine would have to learn at the same pace we do, or from the same sources, or in a similar fashion. Going back to the computer chess analogy, a grandmaster requires years of experience to learn how to play well, while a program can parse a large database of games and learn from them in a matter of hours or days.
* "Moore’s Law will not help." This is retarded. The paragraph goes on to acknowledge that it will help, but computer power is not the whole story. Of course it's not the whole story! But it will certainly help.
* "The hard problem of learning and the even harder problem of consciousness." Machine Learning is a very active discipline, with many recent successes. I don't think learning is a serious obstacle. I don't see a problem of consciousness anywhere. "Consciousness" sounds like a new name for "the soul" to me: It's likely to be an attribute that we assign to people as part of the theory of mind, not an actual thing we need to produce and insert into our machines. In any case, it has very little to do with intelligence.

It won't matter if we know what makes humans intelligent, or what intelligence is, or what consciousness is: The proof will be in the pudding. When you see machines that surpasses humans at most tasks we think of as requiring intelligence, we'll have intelligent machines. And philosophers can continue to argue about definitions all they want.

about 7 months ago

Why Standard Deviation Should Be Retired From Scientific Use

PacoSuarez Re:Standard deviation BAD, but mean GOOD? (312 comments)

I am not sure how I feel about that measure. If we were to use the median absolute error and try to be consistent, we would have to use as the central measure whatever minimizes the median absolute error. That would be a point somewhere between the 25th and 75th percentile, in the "flatter" part of the distribution, in some sense. I don't know if that central measure has a name, but I suspect it's not very relevant in practice.

about 9 months ago

Why Standard Deviation Should Be Retired From Scientific Use

PacoSuarez Standard deviation BAD, but mean GOOD? (312 comments)

Perhaps non-mathematicians don't have a problem with this, but it rubs me the wrong way.

What makes the mean an interesting quantity is that it is the constant that best approximates the data, where the measure of goodness of the approximation is precisely the way I like it: As the sum of the squares of the differences.

I understand that not everybody is an "L2" kind of guy, like I am. "L1" people prefer to measure the distance between things as the sum of the absolute values of the differences. But in that case, what makes the mean important? The constant that minimizes the sum of absolute values of the differences is the median, not the mean.

So you either use mean and standard deviation, or you use median and mean absolute deviation. But this notion of measuring mean absolute deviation from the mean is strange.

Anyway, his proposal is preposterous: I use the standard deviation daily and I don't care if others lack the sophistication to understand what it means.

about 9 months ago

Why Transitivity Violations Can Be Rational

PacoSuarez Re:Totally flawed model (169 comments)

They don't claim to have a realistic model of the situation: They showed a very simple model in which the rational behavior contains an apparent violation of transitivity. And they didn't need to introduce a variety of nutrients to obtain it. This makes their model better, in the sense that it is simpler.

[Sorry, I posted as AC earlier.]

about 9 months ago

No, the Earth (almost Certainly) Won't Be Hit By an Asteroid In 2032

PacoSuarez "The chance of an impact will certainly drop"? (142 comments)

> Bottom line: we do not have a good orbit for this rock yet, and as observations get better the chance of an impact will certainly drop.

What is that supposed to mean? It should get closer to 1 or to 0. It will get closer to 0 with probability .9999998, and to 1 with probability .0000002. So it will not "certainly" drop.

1 year,2 days

Bill Gates Acknowledges Ctrl+Alt+Del Was a Mistake

PacoSuarez Re:Redundant keys (665 comments)

There is no Right Alt key.

Err... I just looked down at my [US] keyboard and there is a key labeled "Alt" immediately to the right of the space bar.

The Compose key is a much better way to handle extra symbols. Sun keyboards used to have a key with that name, and on Linux you can assign one of those useless keys to the right of the space bar (I use "Window") to act as a Compose key. Compose = E to get €, Compose ' e to get é, Compose / l to get , Compose ~ n to get ñ, etc.

1 year,24 days

Study: Our 3D Universe Could Have Originated From a 4D Black Hole

PacoSuarez Re:God needed? (337 comments)

Perhaps I shouldn't answer your question because it is completely off topic, but that argument is just horrible. How does that supernatural entity explain anything? Where did *it* come from?

Not knowing some things is OK. It's certainly better than fooling yourself.

about a year ago

Computer Trading and Dark Pools

PacoSuarez Re:"have to be the same or better" (222 comments)

This usage of "better" is completely standard, and it's always from the point of view of the liquidity taker: A quote is better if it gives the other side a better deal. This is consistent with common language usage.

In other words it means "higher price if it's a quote to buy, lower price if it is a quote to sell". "Better" is a much better word.

about a year ago

Can Valve's 'Bossless' Company Model Work Elsewhere?

PacoSuarez Re:No (522 comments)

Although you are technically correct in that the statement is not as mathematically inevitable as the GP indicated, the concavity of the utility function at the scale of $100 is tiny for most people, and the statement stands.

about a year and a half ago

Senators Seek H-1B Cap That Can Reach 300,000

PacoSuarez Re:Definition of a cap (605 comments)

I went through this ridiculous process to get my green card. I had been working for my company for 6 years with an H1-B visa. I am a smart guy, I get along with everyone in the group, I know the system we work on in and out. I haven't seen the adds they ran, but I wouldn't be surprised if they looked like what's described in that video. Why would the company be interested in firing me and hiring someone else that comes with huge uncertainties and with months of training to get up to speed?

It gets even more ridiculous than what's in that video. Over the years, immigration lawyers have learned what requirements they can get away with listing in the add. For instance, I have a M.S. degree, but they couldn't list it as a requirement because I am not a manager. Of course there is no connection between being a manager and having a M.S. degree, but I guess this makes sense if you posses a lawyer's brain.

There are two things that don't match your story, though:
  (1) My salary is not low by any standards.
  (2) The company has hired people that responded to these "fake adds", because the scarcity of good candidates is real. They just had to come up with some excuse why the candidate wasn't qualified for that specific job, and then offer him a different job.

It's all a strange dance, where the government knows and understands what the company is trying to do and why, but the government has to keep the appearance of being protecting the U.S. workers. The solution is to stop requiring these ridiculous adds.

about a year and a half ago

When Was the Last Time You Used a Landline Phone?

PacoSuarez Re:This Month/This Year? (329 comments)

No! It's plural, so "minutia".

about a year and a half ago

Analytic Thinking Can Decrease Religious Belief

PacoSuarez Re:Whoever is responsible for this article (1258 comments)

Perhaps you can read the whole chapter, and you'll see that the sentence is uttered by a king in a story that Jesus was telling. It still seems like the king is being portrayed positively by Jesus, so the message remains contradictory, but you shouldn't remove the context so blatantly.

more than 2 years ago

How and Why Wall Street Programmers Earn Top Salaries

PacoSuarez Re:HFT borderline illegal (791 comments)

HFT is somewhat illegal, since it could be considered insider trading, since you have time to process information before it becomes available to other people thanks to a faster network infrastructure.

You probably would also complain if you were playing soccer against people that run faster than you. It's not fair!

There is no insider trading If everyone in the market has access to the same information. You'll try to process it as quickly as possible and do something as smart as possible with it. If you are not fast enough or smart enough, you don't need to be in this business. Trading is not an amateur activity.

more than 3 years ago

Online Call To Shoot President Ruled Free Speech

PacoSuarez How beautifully absurd (395 comments)

> The observation that Obama 'will have a 50 cal in the head soon' and a call to 'shoot the [racist slur]' weren't violations of the law [...]
That sentence alone implies that in the U.S. death threats are protected free speech, but you can't use the word "nigger". I love it.

more than 3 years ago


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