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Completely agree. Some of the tools for interpretability can be useful (particularly for debugging), but I think the broader idea that we always need to be abl
by mgpc 6y ago
Completely agree.
Some of the tools for interpretability can be useful (particularly for debugging), but I think the broader idea that we always need to be able to understand our own models is basically wrong.
For example, if you want AlphaGo to explain why it made a particular Go move, what kind of an explanation is possible? In many cases the only explanation may be that the move leads to a higher probability of a win. There simply may not be a more “compressed” or “high level” answer. Even human Go players often cannot explain why they choose particular moves, other than references to shape and feel, which is basically another way of saying their evaluation of the move leads to a higher win probability. There are a lot of domains where we may just have to accept that that _is_ the explaination.
To zoom out a bit, our greatest discoveries have historically been about finding the rare places where the universe is computationally compressible. Boiling a kettle is almost unimaginably complex to describe in terms of the interaction of elementary particles. But you can make very good predictions about that process using an equation that fits on a cocktail napkin. There may be other areas in which the universe is compressible only to a lesser extent. The parameters of AlphaGo are vanishingly small compared to the size of the Go game tree, but are very large compared to the equation we can use to predict the kettle. There may be many problems where the best descriptions lie in this intermediate domain, a domain which we have never really had access to before (except via biological brains).
So if learned models give us access to some truths without access to their (human intelligible) explanations, I think we need to just embrace that. If you allow yourself a new way of seeing, you can see new things.
- brazzy 6y ago> So if learned models give us access to some truths without access to their (human intelligible) explanations, I think we need to just embrace that. The question is: if the model is not interpretable or understandable, how do you know that what it gives you is, in fact, truth? You basically need some kind of external validation of the results. In the case of Go, the rules of the game and competion basically provide that in a very authoritative way. I don't think this is the case for all that many domains. As I see it, behind the desire for interpretability there are two main concerns: * could a model that gives really good answers in all the cases we have tested still give catastrophically wrong answers in some cases we have not foreseen? * could the model be relying on some flaw or bias in the training data which we haven't realized?