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A Kaggle Grandmaster cheated in $25k AI contest with hidden code

theregister.co.uk

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Re: A Kaggle Grandmaster cheated in $25k AI contest with hidden code

#181

Post by endorphone »

blurps wrote: post #174
endorphone wrote: post #70

Earlier quoted context omitted.

The Netflix Prize was interesting, and drew a lot of attention to it, but ultimately wasn't that simply stuffed into the trash bin? Not long after that, Netflix basically abandoned both user ratings of significance, and realistic recommendations. Now it's just a nonsense engine with some sort of meaningless overlap or whatever they call it.

> into the trash bin? They did not implement the winning solution as is, but a lot of good stuff came from the winning teams, including techniques (such as SVD) that are in use as of today (or maybe a few years back). > just a nonsense engine No, it is safe to assume the recommendation engine of Netflix is close to the state-of-the-art. A lot of money and talent went into it.

"They did not implement the winning solution as is"

Shortly after that contest finished Netflix removed the five star rating system, and dramatically subdued the recommendation engine. Now the vast majority of the content surfacing is universal beyond some small category filtering (e.g. You like crime dramas and horrors so here's a bunch of the most popular stuff from those categories).

Now they have a "match" rating that I have not met a single person who finds useful (it is almost at the point of farce and seems more like a randomization engine).

A lot of money and talent went into something that Netflix clearly decided just wasn't important or useful enough for them. Now they just push Don't F*ck With Cats on everyone.

Re: A Kaggle Grandmaster cheated in $25k AI contest with hidden code

#182

Post by cr0sh »

jl2718 wrote: post #171
Tenoke wrote: post #120

Earlier quoted context omitted.

>Was this historically, always like this? Of course. 20$ bills left on the floor are bound to be picked by someone even if most won't. ..At least as long as the expexted punishment comes down to less than the value of said bills.

I have a 5€ note I found blowing in the wind while running at an abandoned construction site. I asked everybody in the vicinity if they dropped it, but I still feel awful about picking it up, because I didn’t and don’t feel I can do justice by dropping it. It’s made me realize I may have moral failures from earlier in my life that I never bothered to commit to memory because I wouldn’t have thought of them that way.…

I'm not sure why you should feel guilt here - you actually went above and beyond what most people would have done in the situation. Most people, finding money on the ground that nobody was trying to pick up themselves, would have just picked it up, pocketed it, and walked on.

And honestly, there should be no guilt in that. Now, had there been someone going around saying "hey, I had this money here and the wind blew it out of my hand, have you seen it?" - and they named the denomination or something that made you know that the money you picked up belonged to them - and you didn't say "why yes, I found this over there; here you go!" and handed it back...well, you should feel guilty knowing you had taken their money - even if they didn't see you do it.

But if nobody is actively looking for it, then heck - what can you do, and why feel guilt over it? Sure - you could have left it lying there, and if everyone did that, maybe somebody could retrace their steps to find where they dropped it?

Or for all you know, it was dropped, not noticed, and the wind or a passing vehicle picked it up and flung it hither and thither and even if the person knew they had dropped it, they had no way of finding it. You could feel guilt - but now you are feeling guilty over something that is virtually unknown to you; you don't even know if the person who lost it even knows they did, or if they even care...

But again - it's a different thing if you see it happening. As a kid (I was probably 12 years old), I was once in a bowling alley when I was walking behind a man, and I noticed a large amount of money (bills) fall out of his back pocket, and he didn't even notice one bit. We're talking several 50 dollar bills. I saw it. I saw him walk on. I went over to pick it up. It was a lot of money...

I grabbed it all and ran to him, "Mr! You dropped all of this!" and handed it back to him; he was super thankful. I was glad I did it, because I know most other kids wouldn't have done that - heck, there are adults who wouldn't.

But I had seen the money fall out of his pocket - I knew it was his. Had I kept it, I know I would have been stealing from him, and would have felt guilty. It was the right thing to return it without any expectation. To this day (decades later) I am glad I did what I did - that very well could have been his paycheck for all I know.

Now - had (somehow) that pile of money been there and I saw it, and nobody else had claimed it? Well - even today I'd probably take it to the "lost and found" - somebody loses that kind of money (or item - like a wallet, phone, etc) - that's the right thing to do. Only if nobody ever claims it, and it's returned to you as "unclaimed" - should you take it. Even then, maybe it would be better to donate it to a good cause than to keep it.

Definitely an ethical and moral dilemma - and here I don't know if I've just refuted myself, or whether I have helped anything for you, or if I've just made myself question my own failings or faults. Probably a bit of everything - and maybe that's for the best. So thank you for your post - I think.

Re: A Kaggle Grandmaster cheated in $25k AI contest with hidden code

#183

Post by zentiggr »

luma wrote: post #156
bleuarff wrote: post #155

Earlier quoted context omitted.

That's not a hack, that's blatant cheating, their solution litterally looked at the anwsers. It bypassed the ML model prediction, so that's not a ML solution, which to my understanding was the constraint of the competition. And in the end, that solution is useless for the adoption site, since the objective is to get adoption predictions (the animal has not been adopted yet). I'm confused too, by how can anyone think…

Their solution made use of the data available to them in a "prize" that was nothing more than a made-up competition for fun. Did the rules expressly say somewhere that one could not make use of available datasets?

I think you misunderstood that the team in question scraped prospective test profiles from the website in question outside of the competition data flow. They blatantly cheated the competition process using data that was not supposed to be available to them.

Re: A Kaggle Grandmaster cheated in $25k AI contest with hidden code

#184

Post by dlkf »

AstralStorm wrote: post #176
KaoruAoiShiho wrote: post #170

Earlier quoted context omitted.

AFAIK it's impossible to smuggle it in a way that you can't be caught. Maybe the use of MD5 made it easier to see but if examined I don't think there's a totally hidden solution.

Yes, he could have trained a network to recognize them and return memorized values. It would not be nearly as obvious. Solving this would require changing the contest so that it comes with algorithm and instructions only (no data files, entropy checks) and is trained by contest operators.

This would also be very fishy to anyone who inspects the source code. Immediately they would ask "uh where did this giant file of floats come from?"

One approach would be to write some handcrafted rules/features that look likecthey were plausibly a priori, but have the effect of memorizing the scraped data. (I don't know if this is actually possible.)

User KaoruAoiShiho is probably right that any approach along would look out of place. Coupled with the fact that its removal would massively boost accuracy, it's hard to imagine how this would get past a curious reviewer.

Perhaps peer review should be a component of the Kaggle process.

Re: A Kaggle Grandmaster cheated in $25k AI contest with hidden code

#185

Post by koheripbal »

paulgb wrote: post #17

For an HN audience, the "How Bestspotting cheated" post on Kaggle may be a better place to start: https://www.kaggle.com/bminixhofer/how-bestpetting-cheated

Is it me, or has the HN user-sphere changes significantly this year.

I feel as though comments are less informative, more judgemental, and chalk full of emotions.

...as if a younger crowd of users has started using it.

Have the older-wiser HNers started using another site?

Re: A Kaggle Grandmaster cheated in $25k AI contest with hidden code

#186

Post by aratauto »

iudqnolq wrote: post #95
harry8 wrote: post #62

Earlier quoted context omitted.

They scraped data from the website of the org that wanted the results and funded the competition. That data was supposed to be unseen for the competitors and used to grade the models. This cheat was to use that scraped data in its training set and, beyond that, hard code some predictions. It's looking up the answers in the grading sheet while taking an exam.

Your parent is saying kaggle takes the training code and runs it themselves. This makss secretly training on the known right answers impossible.

This competition allowed submissions to include extra data files that can be used by the model. The cheaters added a file with data from another website that seemed innocent, but secretly encoded extra information (perfect answers) in IDs. For 10% of predictions, the code via a set of obfuscated operation retrieved this information and presented it as the answer.

Re: A Kaggle Grandmaster cheated in $25k AI contest with hidden code

#187

Post by meowface »

anoncareer0212 wrote: post #85
gojomo wrote: post #71

Before reading they'd scraped public data that was likely to be the "hidden" evaluation set, I thought they might have cheated using Python introspection: inspect the caller's frame, find some variable already loaded with the expected answer, return that. Has anyone cheated at Kaggle/similar using that approach?

No, and this pattern of thought is bizarre, lacks technical grounding, and more importantly, scruples

...What? Their post seemed very reasonable. This seems like a valid concern.

Re: A Kaggle Grandmaster cheated in $25k AI contest with hidden code

#188

Post by Can_Not »

luma wrote: post #153
ribs wrote: post #87

It really worries me how many people are so quick to forgive him and tell him so. In my family if someone cheated they got called a cheater and suffered consequences. At least, they would have, if someone did something like that. But my parents didn’t raise mendacious villains. Look at this crap on Twitter: “Everyone makes mistakes. Thank you for the apology”. “Kagglers will still love to have you back” “It's great t…

I'm confused by this reaction here - this was a _brilliant_ hack of the system and I think his work should be celebrated. Was it in keeping with the intention of the competition? Of course not. Were lives threatened by their creative solution to the competition? Also no. At the end of the day it was a fun, inventive approach to a made-up problem. So what's the problem?

That reminds me of another _brilliant_ hack I had my kid do at a youth checkers tournament. I got him to swat the other players pieces off of the board so the opponent would eventually run out of pieces before my child. I think the opposing kids parents were biased against me just because I'm an inventive genius.

Re: A Kaggle Grandmaster cheated in $25k AI contest with hidden code

#189

Post by gowld »

gpm wrote: post #160
sundvor wrote: post #111

Earlier quoted context omitted.

I'm thinking Kaggle should look to Epic/Fortnite for how to handle cheaters. A lifetime ban would not be out of the place here, considering it went on to win the competition with no admission until caught.

Kaggle should be looking to the police on how to handle cheaters. He stole 10,000 dollars, he defrauded h20.ai, etc. That's "go to jail" level crimes, not just "get banned from a competition and fired" level crimes.

He gamed their poorly designed game. He didn't hack their servers.

Re: A Kaggle Grandmaster cheated in $25k AI contest with hidden code

#190

Post by harry8 »

iudqnolq wrote: post #167
harry8 wrote: post #107

Earlier quoted context omitted.

There is no such thing as "training code". You have a model that you have trained on some provided data - the training set. You give kaggle this model. Kaggle grades your model on some different data your model has never seen. The better your model classifies this data it hasn't seen the higher it scores and the more money you win. So again if you trained your model (code) on a training set that you have illegally ob…

> There is no such thing as "training code". I'm by no means an expert in ML, but my understanding is there's some code that is run to train the modal. I meant that by "training code". My regrets if my terminology was unclear. > They took the official training set. Said, we need more. And scraped websites to get a bigger, illegal training set. This is against the rules and is cheating. They got caught. No, this is wr…

No it isn't. See above. Overfittiing to a holdout set is so easy and common you usually need to take steps to avoid it. See my comment directly above. Best.
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