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The Off Topic Topic

Started by Korea, March 10, 2009, 06:24:26 AM

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DGuller

Quote from: Maximus on January 02, 2019, 09:35:38 PM
It's interesting because it may show a fundamental limitation/advantage of purely numeric systems such as neural nets.
If you go by the description in the article, what happened was not some novel failure but rather the one extreme of what can always happen when you build an autoencoder-type network like this.  One of the extreme outcomes is that you learn features that are too simplistic to be useful.  The other extreme outcome is that you memorize the input without simplifying it into relatively few useful features. 

All this article seems to say is that researchers got into the latter extreme during an early iteration of their model.  It's not that uncommon, probably every practitioner accidentally builds a perfect model from time to time, you know to watch out for it.

Maximus

Quote from: DGuller on January 02, 2019, 10:06:10 PM
If you go by the description in the article, what happened was not some novel failure but rather the one extreme of what can always happen when you build an autoencoder-type network like this.  One of the extreme outcomes is that you learn features that are too simplistic to be useful.  The other extreme outcome is that you memorize the input without simplifying it into relatively few useful features. 

All this article seems to say is that researchers got into the latter extreme during an early iteration of their model.  It's not that uncommon, probably every practitioner accidentally builds a perfect model from time to time, you know to watch out for it.
Overfitting and underfitting are indeed uninteresting. I don't see that happening here, though. Rather what seem to have happened is a limitation of their data. They didn't have a X->Y ground truth function because that would require manual labeling which is expensive, so they tried to approximate it with a X->Y->X function.

DGuller

Quote from: Maximus on January 02, 2019, 11:39:43 PM
Quote from: DGuller on January 02, 2019, 10:06:10 PM
If you go by the description in the article, what happened was not some novel failure but rather the one extreme of what can always happen when you build an autoencoder-type network like this.  One of the extreme outcomes is that you learn features that are too simplistic to be useful.  The other extreme outcome is that you memorize the input without simplifying it into relatively few useful features. 

All this article seems to say is that researchers got into the latter extreme during an early iteration of their model.  It's not that uncommon, probably every practitioner accidentally builds a perfect model from time to time, you know to watch out for it.
Overfitting and underfitting are indeed uninteresting. I don't see that happening here, though. Rather what seem to have happened is a limitation of their data. They didn't have a X->Y ground truth function because that would require manual labeling which is expensive, so they tried to approximate it with a X->Y->X function.
The X->Y->X model is what's called the autoencoder model.  The point of that model is for it to predict its own inputs.  Obviously that could be a trivially easy task if your model has enough capacity to just memorize and regurgitate its input, but a meaningful autoencoder would leave you with Ys in the middle that would be a useful simplification of your data. 

The trick is to build it so that Ys capture enough information, and the most useful information, but not so much information that it's just an overly elaborate lossless data compression.  It's very hard to build useful autoencoders, and building rote memorizers is almost inevitable at some point during the development.  That's the analog of overfit supervised models.

Admiral Yi

What do you guys think about the American Civil War?

DGuller

Quote from: Admiral Yi on January 03, 2019, 12:18:18 AM
What do you guys think about the American Civil War?
It was okay.

Valmy

Quote from: Admiral Yi on January 03, 2019, 12:18:18 AM
What do you guys think about the American Civil War?

I think the Army of the Tennessee was an army of bad-asses.
Quote"This is a Russian warship. I propose you lay down arms and surrender to avoid bloodshed & unnecessary victims. Otherwise, you'll be bombed."

Zmiinyi defenders: "Russian warship, go fuck yourself."

Syt

I am, somehow, less interested in the weight and convolutions of Einstein's brain than in the near certainty that people of equal talent have lived and died in cotton fields and sweatshops.
—Stephen Jay Gould

Proud owner of 42 Zoupa Points.

Caliga

Quote from: Admiral Yi on January 03, 2019, 12:18:18 AM
What do you guys think about the American Civil War?
STATES RAHTS
0 Ed Anger Disapproval Points

Habbaku

The medievals were only too right in taking nolo episcopari as the best reason a man could give to others for making him a bishop. Give me a king whose chief interest in life is stamps, railways, or race-horses; and who has the power to sack his Vizier (or whatever you care to call him) if he does not like the cut of his trousers.

Government is an abstract noun meaning the art and process of governing and it should be an offence to write it with a capital G or so as to refer to people.

-J. R. R. Tolkien

alfred russel

Quote from: Admiral Yi on January 03, 2019, 12:18:18 AM
What do you guys think about the American Civil War?

It was neither American, nor Civil, nor a War.

They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety.

There's a fine line between salvation and drinking poison in the jungle.

I'm embarrassed. I've been making the mistake of associating with you. It won't happen again. :)
-garbon, February 23, 2014

alfred russel

Quote from: alfred russel on January 03, 2019, 01:49:05 PM
Quote from: Admiral Yi on January 03, 2019, 12:18:18 AM
What do you guys think about the American Civil War?

It was neither American, nor Civil, nor a War.

Wait, I'm getting that mixed up with the Holy Roman Empire.

It was the Holy Roman Empire that was neither American, nor Civil, nor a War.
They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety.

There's a fine line between salvation and drinking poison in the jungle.

I'm embarrassed. I've been making the mistake of associating with you. It won't happen again. :)
-garbon, February 23, 2014

The Minsky Moment

Quote from: Admiral Yi on January 03, 2019, 12:18:18 AM
What do you guys think about the American Civil War?

Which one?
The purpose of studying economics is not to acquire a set of ready-made answers to economic questions, but to learn how to avoid being deceived by economists.
--Joan Robinson

FunkMonk

Quote from: alfred russel on January 03, 2019, 01:50:02 PM
Quote from: alfred russel on January 03, 2019, 01:49:05 PM
Quote from: Admiral Yi on January 03, 2019, 12:18:18 AM
What do you guys think about the American Civil War?

It was neither American, nor Civil, nor a War.

Wait, I'm getting that mixed up with the Holy Roman Empire.

It was the Holy Roman Empire that was neither American, nor Civil, nor a War.

I'm starting to feel verklempt.
Person. Woman. Man. Camera. TV.

Eddie Teach

To sleep, perchance to dream. But in that sleep of death, what dreams may come?

Syt

I am, somehow, less interested in the weight and convolutions of Einstein's brain than in the near certainty that people of equal talent have lived and died in cotton fields and sweatshops.
—Stephen Jay Gould

Proud owner of 42 Zoupa Points.