Confessions of a researchaholic

March 29, 2012


Filed under: Imaginary,Real — liyiwei @ 7:33 pm
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God is in the details
Devil is in the details
So which one will be there
When we look into the details

March 26, 2012

Another data point

Filed under: Real — liyiwei @ 1:49 am
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In responding to my earlier post, a very talented graphics researcher has shared with me his statistics, as shown below.

As you can see, his has much better success rate than me, especially considering that he has been doing rendering, a tough field for SIGGRAPH. πŸ™‚

March 24, 2012

Fooled by randomness

Filed under: Real — liyiwei @ 11:41 pm
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Feeling down from some recent rejections? I hope this post will make you more positive. The gist: never, ever, quit.

Assume you are throwing N loaded dices, each with a probability p for coming up head.

Now, if p is greater than 0 and smaller than 1, there is always a chance that the N dices will come up with all heads or all tails. And the smaller the N value, the more likely for such extreme cases to happen.

This is all pure chance. But unfortunately, human brains have difficulty accepting randomness, and always want to impose determinism, e.g. patterns or rules or causalities.
For example, if you are a scholar submitting N papers to a conference, you will likely consider yourself to be very good/bad (or the paper committee has treated you very well/badly) if all N submissions are accepted/rejected.

This human fallacy is brilliantly illustrated by Nassim Nicholas Taleb’s book “Fooled by Randomness”.

However, even without reading that book, I can recommend a very simple remedy: law of large numbers. This is a well-known mathematical theorem, which says that the expected value of a random variable can be more accurately predicted by averaging a larger number of samples.

So, for example, to measure your intrinsic paper acceptance rate towards a specific conference, you can take the total number of acceptances divided by the total number of submissions. This will be a much more meaningful measure than your acceptance rate for a single year, especially if you have a sufficient number of submissions across multiple years.

For example, the plot below shows my cumulative acceptance rate for SIGGRAPH, the top venue for computer graphics and interactive techniques. As you can see, the rate seems to be gradually converging to a certain value, around 0.34. This is much more stable measure than my yearly rate, which can be anywhere between 0 and 1.

Now, if you are new to a field, your rate will have a higher variance, just like the initial portions of mine. I was lucky that I had a good start which boosted my confidence. (Initial condition is actually very important and has been found to greatly influence the performance of many careers, e.g. hockey players. Note to myself: dig out that book/article. I guess it should be Geoff Colvin’s “Talent is Overrated” or Malcolm Gladwell’s “Outliers”.) However, if you happen have an unlucky start, do not give up too early; hang on for a while, so that you can have a chance to see your *intrinsic performance*.
As you can see, my intrinsic performance did not really show up until about a decade doing SIGGRAPH.

(With all these rational arguments, I have to confess that it still hurts to get rejected!)

Some notes about the graph: (1) I plot SIGGRAPH at integer years and SIGGRAPH Asia at integer + 0.5 years, (2) missing data points are for years which I did not submit anything (2004 and 2005 while in NVIDIA and 2011.5 when I have nothing to submit for SIGGRAPH Asia 2011), (3) a more accurate measure would be “moving average” (with exponential decay of past values) but I probably need another 10 years to warrant this, (4) I really want to improve my intrinsic rate to at least 50 percent!, (5) I guess the ultimate test is to have multiple disjoint committees + reviewers, all with similar qualities, to evaluate the same batch of submissions, and see if they will accept similar sets of papers.

March 23, 2012


Filed under: Imaginary,Real — liyiwei @ 7:03 pm
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Dear Chinese government:

According to the following statistics, 50% of Chinese men smoke, consuming one-third of the world’s cigarettes.

As you can imagine, this is a significant drag-down of the Chinese national power, given the well known facts about health hazards caused by smoking.

Please put your authoritarian power in good use and ban smoking outright. No, not just in public places, but illegalize cigarettes all together.
Unlike the dysfunctional democracies like America who have to listen to tobacco lobbyists, you have no such baggage. And I am pretty sure no Chinese tobacco kingpin is more powerful than Bo Xilai, whom you sacked with such ease and grace just last week.

You can easily bankrupt the world’s tobacco industry by eliminating one-third of their revenues. This will go down as one of the major achievements in human history.

The last dynasty, Qing, in a much weaker state, had the gut to ban opium. I am pretty sure China is strong enough now to win a second opium war even if some foreign imperial power is stupid enough to start one.

Sincerely yours.

March 20, 2012


Filed under: Imaginary,Real — liyiwei @ 8:45 pm
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Humans seem to have so much trouble accepting the nature of death that they need to come up with all kinds of alternatives like after-life and reincarnation.

“Hell is a place where nothing connects to nothing” – T.S. Elliot

March 3, 2012

Reading week

Filed under: Real — liyiwei @ 4:09 pm

So the university has this *reading week* in the middle of the semester that has all classes suspended. The official documentation says this is for students to catch up on their course readings.

I was wondering why the students need an entire frigging week for this; aren’t they supposed to be doing the reading and course works all the time?

Eventually, a senior professor told me, in a whispering tone: “the reading week is just an excuse for professors to take a spring break”.

Hush, hush


Filed under: Real — liyiwei @ 11:31 am
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Recently I read two good articles about ageism in innovation and entrepreneurship.

The first one, from San Francisco magazine titled “Dark side of the boom”, is really about the dark side of the youth entrepreneurship myth in the valley.

The second one, from The Economist, is about the fact that statistically older people are no less innovative or enterprising than the young.

It is actually not just about the valley or the entrepreneurship. Our cultures, especially the American one, seem to have this mysterious but unfortunate tendency to encourage early success. It is as though success at a young age is a certificate of life long achievement. Child prodigy can be a sign of true genius, but can also be a simple consequence of precocity, a premature biological cycle. Perhaps the most harmful situation is when unnatural forces are applied to fake a genius out of an ordinary individual.

Take your time; it is true that life is short and should not be wasted, but a lot of things simply need time to mature and cannot be rushed, no matter how smart you are.

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