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Lots of problems with this paper including the fact that, even if you accept their claim that internal board state is equivalent to world model, they don't appe
by foobarqux 2y ago
Lots of problems with this paper including the fact that, even if you accept their claim that internal board state is equivalent to world model, they don't appear to do the obvious thing which is display the reconstructed "internal" board state. More fundamentally though, reifying the internal board as a "world model" is absurd: otherwise a (trivial) autoencoder would also be building a "world model".
- sebzim4500 2y ago>More fundamentally though, reifying the internal board as a "world model" is absurd: otherwise a (trivial) autoencoder would also be building a "world model". The point is that they aren't directly training the model to output the grid state, like you would an autoencoder. It's trained to predict the next action and learning the state of the 'world' happens incidentally. It's like how LLMs learn to build world models without directly being trained to do so, just in order to predict the next token.
- optimalsolver 2y ago>It's like how LLMs learn to build world models without directly being trained to do so, just in order to predict the next token That's the whole point under contention, but you're stating it as fact.
- foobarqux 2y agoBy the same reasoning if you train a neural net to output next action from the output of the autoencoder then the whole system also has a "world model", but if you accept that definition of "world model" then it is extremely weak and not the intelligence-like capability that is being implied. And as I said in my original comment they are probably not even able to extract the board state very well, otherwise they would depict some kind of direct representation of the state, not all of the other figures of board move causality etc. Note also that the board state is not directly encoded in the neural network: they train another neural network to find weights to approximate the board state if given the internal weights of the Othello network. It's a bit of fishing for the answer you want.
- IanCal 2y ago> And as I said in my original comment they are probably not even able to extract the board state very well, They do measure and report on this, both in summary in the blog post and in more detail in the paper. > otherwise they would depict some kind of direct representation of the state If you can perfectly accurately extract the state the result would be pretty boring to show right? It'd just be a picture of a board state and next to it the same board state with "these are the same". > Note also that the board state is not directly encoded in the neural network: they train another neural network to find weights to approximate the board state if given the internal weights of the Othello network. If you can extract them, they are encoded in the activations. That's pretty much by definition surely. > It's a bit of fishing for the answer you want. How so? Given a sequence of moves, they can accurately identify which state most of the positions of the board are in just by looking at the network. In order for that to work, the network must be turning a sequence of moves into some representation of a current board state. Assume for the moment they can accurately identify them do you agree with that conclusion?
- foobarqux 2y ago> They do measure and report on this, both in summary in the blog post and in more detail in the paper. I didn't see this in the blog post, where is it? Presumably they omitted it from the blog post because the results are bad as I describe below, which is precisely why I cited it as a red flag. > If you can perfectly accurately extract the state the result would be pretty boring to show right? It'd just be a picture of a board state and next to it the same board state with "these are the same". But they don't! They have nearly 10% tile level error on the human-data-trained model. That's nearly 100% board error. It's difficult to understand how bad this is but if you visualize it somehow (for example sampling random boards) it becomes obvious that it is really bad. On average about 6 or 7 tiles are going to be wrong. With nearly 100% probability you get an incorrect board. > If you can extract them, they are encoded in the activations. That's pretty much by definition surely. No, that's silly. For example you can cycle through every algorithm/transformation imaginable until you hit one that extracts the satanic verses of the Bible. As I said in another comment although it is in theory mitigated somewhat by doing test/validation splits in practice you keep trying different neural network hyperparameters to finesse your validation performance. > How so? Given a sequence of moves, they can accurately identify which state most of the positions of the board are in just by looking at the network. In order for that to work, the network must be turning a sequence of moves into some representation of a current board state. Assume for the moment they can accurately identify them do you agree with that conclusion? What conclusion? I believe you can probably train a neural network to take in board moves and output board state with some level of board error. So what?
- IanCal 2y ago> hey don't appear to do the obvious thing which is display the reconstructed "internal" board state. I've very confused by this, because they do. Then they manipulate the internal board state and see what move it makes. That's the entire point of the paper. Figure 4 is literally displaying the reconstructed board state.
- foobarqux 2y agoI replied to a similar comment elsewhere: They aren't comparing the reconstructed board state with the actual board state which is the obvious thing to do.
- famouswaffles 2y ago>they don't appear to do the obvious thing which is display the reconstructed "internal" board state This is literally figure 4 This also re-constructs the board state of a chess-playing LLM https://adamkarvonen.github.io/machine_learning/2024/01/03/chess-world-models.html https://adamkarvonen.github.io/machine_learning/2024/01/03/c...
- foobarqux 2y agoUnless I'm misunderstanding something they are not comparing the reconstructed board state to the actual state which is the straightforward thing you would show. Instead they are manipulating the internal state to show that it yields a different next-action, which is a bizarre, indirect way to show what could be shown in the obvious direct way.
- famouswaffles 2y agoFigure 4 is showing both things. Yes, there is manipulation of the state but they also clearly show what the predicted board state is before any manipulations (alongside the actual board state)
- foobarqux 2y agoThe point is not to show only a single example it is to show how well the recovered internal state reflects the actual state in general —— analyze the performance (this is particularly tricky due to the discrete nature of board positions). That’s ignoring all the other more serious issues I raised. I haven’t read the paper in some time so it’s possible I’m forgetting something but I don’t think so.
- famouswaffles 2y ago>That’s ignoring all the other more serious issues I raised. The only other issue you raised doesn't make any sense. A world model is a representation/model of your environment you use for predictions. Yes, an auto-encoder learns to model that data to some degree. To what degree is not well known. If we found out that it learned things like 'city x in country a is approximately distance b from city y' let's just learn where y is and unpack everything else when the need arises then that would certainly qualify as a world model.