> I don't follow this. If we have a biased objective function, the model won't surface any biases we weren't already cognizant of in the objective function. And they were already quantifiable: we had a function that we were using to evaluate the model. We could use that same function on whatever non-model evaluation we were doing.
We can actually follow the logic of the model. For instance, you can theoretically de-bias a dataset by building a racial classifier from it. What you need is an objective test for the presence of racial information, and that's easy to obtain: Build a classifier to explicitly predict race from your feature set. Train an adversarial model to reconstruct your dataset with maximum fidelity, subject to the constraint that race can no longer be predicted from it.
> This is basically directly in contradiction to what leading experts on the subject say. ML cannot fix bias in human systems, unless we presuppose that those systems are biased, in which case we can often address the bias in the human systems directly without ML.
These experts are just wrong, then. Naive ML won't fix bias in human systems, but that doesn't mean we can't use ML to fix it, if we do so thoughtfully.
> You can still have decisions be made by objective expert systems without complex ML. If you want to learn someone's IQ, the best way is to debias the IQ test, not to try and infer it from their face bones.
Sure, but there are a lot of things that we don't do in the best possible way because it's too expensive. There are lots of use cases for cheap, scalable, low precision models.
> If we can measure the bias in the output of an ML model, we can equivalently measure the bias in the output of a human system. You're presupposing the existence of some unbiased objective function which we don't have, and that's at the core of the issue.
Right, but we cannot fix the bias in a human. And humans are heterogenous and inconsistent. The same person may be more or less biased on different days. The ML model is consistent, and we can incrementally improve its bias in tangible and testable ways. The same is not true of humans.