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Why are we using black box models in AI when we don’t need to? (2019)

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Re: Why are we using black box models in AI when we don’t need to? (2019)

#61
post #43

It's not that accuracy will always be sacrificed if one wants an explainable model. The point is: if interpretability is an important constraint, it could prevent improvements on accuracy. Sometimes, the best interpretable model is as good as a black box, and that's great. When this is not the case, the trade-off is that one should see what's more important for the actual problem. Perhaps interpretability is not a bi…

This is a great point. There is a general lack of understanding about what it means for models to be interpretable & explainable. These words get thrown around often by people who don't understand the definition, and also the trade off with accuracy.

Some papers i found interesting on the subject:

https://arxiv.org/abs/1606.03490

https://arxiv.org/abs/1707.03886

https://arxiv.org/abs/1806.07552

https://arxiv.org/abs/1702.08608 (i found this was a good sumary of the issues)

Re: Why are we using black box models in AI when we don’t need to? (2019)

#62

Earlier quoted context omitted.

> So uhhh, isn't this like not science? Very little of technology has anything to do with validating hypotheses. > meaning that humans, even those who design them, cannot understand how variables are being combined to make predictions. The intention is to not rely on the explanation to evaluate the effectiveness of the model. This does not preclude any of the infinite narratives that might explain the model. This is…

At our company, we are working with "mechanistic" or mathmatical models rather than stastical approches. I have observed : 1. It is hard than it should be to explain the concept to people (particularly VCs) 2 . people struggle to understand that a mechanistic model could have more utlity than a machine learning black box 3. people think you are doing something wrong if you are not using a neural network 4. The less p…

Do you mean like symbolic regression or algorithmic information theory based stuff?

If so, I'd love to get in touch, shoot me an email

Re: Why are we using black box models in AI when we don’t need to? (2019)

#63
post #14

Earlier quoted context omitted.

It’s not like your bank manager used to give you a phone call to explain in depth why your loan was declined. Most of these situations were already impenetrable from a human standpoint. Humans are far more ‘black box’ than neutral nets, we just happen to be able to construct plausible explanations in parallel.

No, they were impenetrable from the customer perspective, but either the human making the decision or the software being used can answer. With a black box model, nobody can answer.

From the post I responded to:

> the scary thing is when decisions are being made that will affect a persons life but will never make it to the courts. Like the example of predicting loan defaults or parole releases, those decisions are made with little to no explination.

I was pointing out that it’s already like this. Whether it’s a black box ML model or a capricious bank employee makes no difference if there’s no transparency either way.

Re: Why are we using black box models in AI when we don’t need to? (2019)

#64

I've happen to be in that workshop room and had chosen the 2% robot, not the 15% surgeon. If I remember correctly, the point of the question was determining willingness of society to use black box models, not challenging the need for models interpretability. Interpretability obviously doesn't hurt accuracy. But it is costly to engineer. And not always possible to make. Not always possible, because human capacity (and…

>> Interpretability obviously doesn't hurt accuracy.

Why do you say this? From what i have seen it certainly can and does. For some industries finding a trade off where the magic is.

https://link.springer.com/article/10.1007/s10664-018-9638-1

https://www.oreilly.com/ideas/predictive-modeling-striking-a...

Re: Why are we using black box models in AI when we don’t need to? (2019)

#65

Earlier quoted context omitted.

At our company, we are working with "mechanistic" or mathmatical models rather than stastical approches. I have observed : 1. It is hard than it should be to explain the concept to people (particularly VCs) 2 . people struggle to understand that a mechanistic model could have more utlity than a machine learning black box 3. people think you are doing something wrong if you are not using a neural network 4. The less p…

Do you mean like symbolic regression or algorithmic information theory based stuff? If so, I'd love to get in touch, shoot me an email

We are using biophysics based approaches. Will send an email over :)

Re: Why are we using black box models in AI when we don’t need to? (2019)

#66
This is a pointless article. Obviously everyone would prefer fully interpretable models if it was possible to get comparable performance with the leading black box/deep learning approaches. No one chooses to make black box, non-interpretable models, it's simply the fact that the models that give the best performance tend to be black box. There is a lot of work happening on trying to interpret deep learning models, because no one prefers non-interpretable models and being unable to pin point and explain why some prediction was wrong.

Re: Why are we using black box models in AI when we don’t need to? (2019)

#67

This is a pointless article. Obviously everyone would prefer fully interpretable models if it was possible to get comparable performance with the leading black box/deep learning approaches. No one chooses to make black box, non-interpretable models, it's simply the fact that the models that give the best performance tend to be black box. There is a lot of work happening on trying to interpret deep learning models, be…

The article explains that their fully interpretable model actually got within 1% accuracy of the best black box model. Which was within cross validation error. That was at a data science competition whose explicit goal was to encourage people to explain black box models. They also give other examples of cases where people have used black box models unnecessarily.

Re: Why are we using black box models in AI when we don’t need to? (2019)

#68

> [...] these black box models are created directly from data by an algorithm, meaning that humans, even those who design them, cannot understand how variables are being combined to make predictions. So uhhh, isn't this like not science? Like my biggest problem with "machine learning" is people assume the data they have can correctly answer the question they want to answer. If your data is off, your model might be in…

I think you are missing the key part of the appeal here (or framing it as a negative).

Let's look at your question. Writing an equation for a cat is hard, actually really hard. Humans cannot reliably explain their decisions here. If I ask a person to tell me how they classify between cat and not cat, the answer will invariably be something along the lines of "well, it has the general shape of a cat". Which is actually just a huge combination of heuristics it took about 10 years to work out. There is quite a lot of work in neuroscience suggesting that the actual decision you make when you classify a cat happens before a rational is developed.

We could encode a function for that, but it relies on us knowing a lot about cats, which takes time and only works for toy examples.

If you use a convolution neural network, you can get close to human level performance on much more complex topics with little domain specific insight. There is no universal law for classifying hand written letters - they are an individual's interpretation of some symbols we made up. This task will always be 'non-rigorous' because the very underlying thing is not actually well defined. When does a 3 become an 8?

So we could have a person toil away and come up with a bunch of heuristics that we encode in a regression, but why is this better than having a machine learn those heuristics? Most problems are not life or death. What is the real added value in having people hand crafting features for predicting traffic jam delays or customer retention, when the end use is probably just to have a rough indication.

As somebody who does research using a huge range of models, I object that we should be guided by our intuition- our intuition is mostly wrong about non trivial problems.

Basically any "equation" somebody has discovered for what happens in a neutron star is "simple". There is a large amount of observational data, it is a consequence of some already well proven theorem, or relies on something well established to narrow the range of possible descriptions immensely, or (most commonly in my experience) the equation is basically a human version of deep learning, where grad students toil away making tweaks and heuristics until a point that the description fits the data somewhat well, and then there is some attempt to ascribe meaning after the fact.

For example, we can describe the trajectory of a comet using a "few" lines of high school level math. This means it is actually feasible for a person to have a reasonable intuition about what is happening, as the problem is actually dominated by a handful of important variables. Good luck getting anywhere near simple to describe cats (again, in a domain where the line of what is and isn't a cat is actually not even a property of it's physical attributes, so the problem is not properly defined under your requirement). To tell if something is or is not a cat, would require a DNA sequence. That is how we define the cat. So by your own definition, we do not have sufficient data in our dataset to properly do this classification.

I'm not sure you really understand the point you make about "statistical tests for bullshit". Most statistical tests are themselves ivory towers of theory and assumption which nobody ever verifies in practice (which is as unsciency as anything you accuse machine learning of). And people do actually use well grounded ways of evaluating machine learning models. Cross validation is very common and predates most machine learning, and has various "correctness" results.

For any model we build, if we do not have data that encodes some pathological behaviour we can test it out on, there is no test, no statistical procedure to tell us that model is flawed. If we have that data, we can run the exact same test on a black box model.

You should not conflate science with formalism or complexity. Running a statistical test is pseudoscientific unless you do it correctly and appropriately.

Saying something is not scientific because the data may not contain enough information to fully answer the question is flat out wrong.

Re: Why are we using black box models in AI when we don’t need to? (2019)

#69

> [...] these black box models are created directly from data by an algorithm, meaning that humans, even those who design them, cannot understand how variables are being combined to make predictions. So uhhh, isn't this like not science? Like my biggest problem with "machine learning" is people assume the data they have can correctly answer the question they want to answer. If your data is off, your model might be in…

> could pen an equation (model) on how to spot a fucking cat or a hotdog without AI? Of course someone could

I had a philosophy lecturer who would vehemently disagree that it is even possible to construct an algorithmic AI to decide what is and isn’t a cat.

For a start, do you mean domestic cats, or the cat family? What about photos, sculptures and other representations?

I mean, is Garfield a cat?

People use statistical machine learning over algorithmic AI because trying to model the real world with algorithms is an endless and often pointless exercise.

Re: Why are we using black box models in AI when we don’t need to? (2019)

#70

I think it's important to note that human pattern recognition is basically black-box as well. We can't "explain" how we recognize a particular person's face, for example. Robust pattern recognition based on 100+'s of factors is just inherently black box. Even when people make decisions, they're generally a weighted combination of a bunch of "feelings". We attempt to explain a kind of simple, logical rationalization a…

> because despite being less accurate, they can have designers who can be held legally accountable and liable

Are you implying you cannot be held accountable for black box models?

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