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AAAS: Machine learning 'causing science crisis'

bbc.co.uk

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Re: AAAS: Machine learning 'causing science crisis'

#71
post #4

Is machine learning really to blame for the reproducibility crisis? I'm not in academia, but it seemed to me that the problem was entirely present without machine learning being involed. For example, Amgen reporting that of landmark cancer papers they reviewed, 47 of the 53 could not be replicated [1]. I would have assumed that most of them didn't involve 'machine learning' [1] https://www.reuters.com/article/us-scie…

Machine learning trivializes p-hacking. Take a database of random datums. Pick e.g. 3 input datums at random and map them against one manually chosen output datum. Run the machine learning system and observe the error rate. If it decreases below some value 'p' you now have a [most likely completely spurious] correlation. Spin up an explanation for it - the more sensationalized the better. Claim that the process was done in the reverse order, claim it's science, publish -- you now have a ground breaking hypothesis that was validated by experimentation.

One of the big reasons that the more modeling, variables, and filtering in a study - the more you should discount it. It's too easy to prove something when there's nothing actually there.

An even bigger risk here is that you can engage in the above process and spot check against other data sets to see if it can be validated elsewhere. And you can find correlations that are predictive, yet are in no way whatsoever causal. If we took a sample with enough data on all individuals in the US you'd be able to find some correlation that people who have an E as the second letter in their name, a last name of five characters in length, and went to a high school whose third letter is 'A' have a 23% higher earned income average than those outside the group. And it predicts going forward.

You'd be mapping onto something that obviously has nothing to do with these variables in and of themselves. Perhaps the real issue would be it's simply a very obscure proxy to a certain group of individuals in a certain subset of educational institutions. But the problem is that this is only obviously spurious (even if predictive) because these sort of variables clearly cannot have any sort of a causal relationship. When instead you only look at a selection of variables that, in practically any combination, could be made to seem meaningful through some explanation or another - you open the door to completely 'fake' science that provides results and even predictivity, but has absolutely nothing to do with what's being claimed. So people might try to maximize towards the correlations (which are/were predictive) only to find nothing more happens than if people started actively making sure the second letter of their children's name was an E and legally changed their last name to 5 letter ones.

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As a pop culture example of this something similar to this happened with video game reviews. Video game publishers noticed that there was a rather strong correlation with positive game reviews and high sales. So they started working to raise average game scores through any means possible, eventually including 'incentivizing' game reviewers to provide higher scores. As a result game reviews began to mean next to nothing, and the strength of the correlation rapidly faded. Because obviously the correlation was never about high review scores, but about making the sort of games that organically received high review scores. Though in this case we already see "obviousness" fading, since there was some argument to be made that the high review scores were what was driving sales in and of themselves - though that was clearly not the case.

Re: AAAS: Machine learning 'causing science crisis'

#72
post #4

Is machine learning really to blame for the reproducibility crisis? I'm not in academia, but it seemed to me that the problem was entirely present without machine learning being involed. For example, Amgen reporting that of landmark cancer papers they reviewed, 47 of the 53 could not be replicated [1]. I would have assumed that most of them didn't involve 'machine learning' [1] https://www.reuters.com/article/us-scie…

No but it’s making it worse because it’s giving false confidence in results and amplifying failures in experiment design. It’s also been held out as a fix for the reproducibility crisis but just as lots of statistical analysis has been done by people who don’t really understand the math but are just cargo culting other experiments, machine learning is taking that ignorance-of-your-toolset risk to the next level. Not…

  Not even the people who write the software understand what patterns are being found. All they can do is point to the results that seem good at a glance. 
This isn’t really true. For example, we can pass in an image to a convolutional net and see which filters are activated; this can give us a clear indication if it’s edge detectors that are activating or textures or specific shapes (eg a dog would activate edge detectors, textures that look like fur, and shapes that resemble a dogs face). We can also train models to disentangle its representations and make specific variables stand for specific things (eg for a net trained on handwriting,values in one variable can represent the slant of writing, another one the letter, another the thickness, etc.). There is also a ton of work being done in training causal models. We also have decent ways now of visualizing high dimensional loss surfaces.

the field has come a long way since 2012, and the whole “it’s magic, we don’t understand why it works or what it learns” is no longer true.

Re: AAAS: Machine learning 'causing science crisis'

#73
post #6

Fails to touch on the perverse incentives in academia, "publish or perish" etc. Torturing a dataset to find a p value that a journal will like (or equivalent stat measure) is better for your career than not publishing a paper that will be discredited in time. You have no incentive at all to decide "my results are unconvincing at this point, I'm not going to submit them" and every reason to write them up as a useful c…

Publish or perish is gone. The NIH is no longer the funding source of choice, now it is pharma or private donors. These people want large impressive datasets, not publications. You can rent out data to pharma without having to publish anything. These don't even have to be useful datasets, mere size is enough to make them valuable to greedy prospectors with lots of cash. Then they can plumb them for bunk results ad infinitum.

Re: AAAS: Machine learning 'causing science crisis'

#74
post #4

Is machine learning really to blame for the reproducibility crisis? I'm not in academia, but it seemed to me that the problem was entirely present without machine learning being involed. For example, Amgen reporting that of landmark cancer papers they reviewed, 47 of the 53 could not be replicated [1]. I would have assumed that most of them didn't involve 'machine learning' [1] https://www.reuters.com/article/us-scie…

No but it’s making it worse because it’s giving false confidence in results and amplifying failures in experiment design. It’s also been held out as a fix for the reproducibility crisis but just as lots of statistical analysis has been done by people who don’t really understand the math but are just cargo culting other experiments, machine learning is taking that ignorance-of-your-toolset risk to the next level. Not…

Some of the points are true specifically the last part but you are wrong about the fact that people who write these software doesn't understand what patterns are being found. We can clearly see in ML and Deep models why the decision was made by the hypothesis using various libraries such as eli5, Tensorboard and others. Deep Learning models are in general harder to debug but still possible.

Therefore we know why hypothesis produces wrong results but sometimes it not possible to mend the model due to outliers, rare events, lack of data and/or randomness that surrounds our world. Just as you point out that statistical analysis is done by people who don’t really understand the math, these false result can be due to scientists using ML without understanding its advantages and limitations.

Re: AAAS: Machine learning 'causing science crisis'

#75
post #60

Earlier quoted context omitted.

Medicine may be better than ML but there’s not much in the difference. > COMPare: Qualitative analysis of researchers’ responses to critical correspondence on a cohort of 58 misreported trials > Background > Discrepancies between pre-specified and reported outcomes are an important and prevalent source of bias in clinical trials. COMPare (Centre for Evidence-Based Medicine Outcome Monitoring Project) monitored all tr…

I am just in the process of digging into this paper and covering it in an article, so I'm quite familiar with it. But as bad as this is: What the COMPare project is doing here is documenting the flaws of a process to counter bad scientific practice. The reality in most fields (including pretty much all of CS and ML) is that no such process exists at all, because noone even tries to fix these issues. So you have medic…

its quite a stretch to say that CS does not have reproducibility ! .. probably want to define that a bit

Re: AAAS: Machine learning 'causing science crisis'

#77
post #71
post #4

Is machine learning really to blame for the reproducibility crisis? I'm not in academia, but it seemed to me that the problem was entirely present without machine learning being involed. For example, Amgen reporting that of landmark cancer papers they reviewed, 47 of the 53 could not be replicated [1]. I would have assumed that most of them didn't involve 'machine learning' [1] https://www.reuters.com/article/us-scie…

Machine learning trivializes p-hacking. Take a database of random datums. Pick e.g. 3 input datums at random and map them against one manually chosen output datum. Run the machine learning system and observe the error rate. If it decreases below some value 'p' you now have a [most likely completely spurious] correlation. Spin up an explanation for it - the more sensationalized the better. Claim that the process was d…

No one uses or needs ML for overfitting 4 variables. You can do that with regular statistics just fine. And how you interpret ML results is just as fraught with error as any statistical argument—just because the technique gives you some result doesn’t mean it’s explanatory, that is science 101.

Re: AAAS: Machine learning 'causing science crisis'

#78
post #76

My impression from the article was that the doctor stating those opinions has no idea how ML works and how to apply it properly, leading to statements like that. "ML gap" is real I guess...

At least (s)he's realizing that (s)he has no idea. Most of the non-math/non-statistics (probably even some of the CS) people don't do that and just apply some ML-algorithm out of a tutorial on their data.

Re: AAAS: Machine learning 'causing science crisis'

#79
post #34

Case in point : LHC Higgs results - how many detection's vs how many events? How were the detection's determined... The answer is with a large booster [1] I postulate that out of 12 billion random events it would be remarkable if a booster didn't extract 100 or so items that looked similar to a Higgs detection. Well, let's give it 20 years and a new generation of PI's who aren't invested in this and have grad student…

You clearly have no idea what you are talking about. Did you try reading any of the papers we wrote? There are many analyses and multiple channels.

Re: AAAS: Machine learning 'causing science crisis'

#80
post #18

Earlier quoted context omitted.

This is the unfortunate truth. Furthermore, those who take more time to find a general, robust and theoretically sound result (beyond just the p-optimized publishable result), get filtered out of te tenure positions as not have a high impact factor, despite their papers in fact having a higher impact.

You may have meant "bullshitable result".

They aren’t mutually exclusive
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