I suppose you’re talking about this paper (https://arxiv.org/abs/2210.10760). It’s important to note that in the setting of this paper, the reward model is only trained on samples from the original policy, whereas GAN discriminators are constantly trained with new data. Section 4.3 touches briefly on the iterated problems, which is closer in setting to GANs, where we correspondingly expect a reduction in overoptimization (i.e the beta term).
It is definitely true that you have to be careful whenever you’re optimizing any proxy metric, and this is one big reason I feel kind of uncomfortable about proposals like RLHF/RRM. In fact, our setting probably underestimates the amount of overoptimization due to the synthetic setup. However, it does seem like GAN mode collapse is largely unrelated to this effect of overoptimization, and it seems like gwern’s claim is mostly about this.
I suppose you’re talking about this paper (https://arxiv.org/abs/2210.10760). It’s important to note that in the setting of this paper, the reward model is only trained on samples from the original policy, whereas GAN discriminators are constantly trained with new data. Section 4.3 touches briefly on the iterated problems, which is closer in setting to GANs, where we correspondingly expect a reduction in overoptimization (i.e the beta term).
It is definitely true that you have to be careful whenever you’re optimizing any proxy metric, and this is one big reason I feel kind of uncomfortable about proposals like RLHF/RRM. In fact, our setting probably underestimates the amount of overoptimization due to the synthetic setup. However, it does seem like GAN mode collapse is largely unrelated to this effect of overoptimization, and it seems like gwern’s claim is mostly about this.