This looks great! Let me see if I understand the big picture correctly (omitting some of your experiments to just get the main thrust):
You finetuned GPT-3.5 alternatively to output the correct answer 1) on 500 MMLU questions, and 2) on debates between copies of GPT-4o on those same 500 MMLU questions. You found that validation accuracy judging debates was better than answering blind.
This difference did not appear when using GPT-4o as a judge, suggesting that in the capability asymmetric case, the judge learned to rely on the debate, whereas in the capability symmetric case, it did not.
Testing this trained judge with different debaters, you find that Elo of the debater models and accuracy of the debate result track well with each other. Strangely though, Best-of-4 decoding on the debaters does not seem to increase Elo?
This shows an example of a case where judge training in case of capability asymmetry actually seems to produce the desired behavior in debates (i.e., the judge relies on the debate and can use it to generalize well). Main issue that comes to mind:
I worry about how much of what we’re seeing is just an effect of domain shift. Since you trained the model on GPT-4o debates, I would expect the accuracy on these debates to be highest, and changing to GPT-4o mini and then GPT-3.5 should lead us further out of domain, reducing the judging model’s accuracy. Then the accuracy trend just reflects how OOD the debates are, and that happens to track with model skill for the debaters you tested. The fact that Elo also tracks in the expected way is a bit harder to explain away here, and makes it seem like the judge is learning something meaningful, but I am pretty unsure about that.
I think I would see these results as a lot stronger if BoN panned out and showed the expected Elo/accuracy relation, but it seems like it does not.
What do you think of this? Anything I’m wrong about or missing here?
Also low-level question. You say above the Elo/accuracy plot:
the Elo in the blue plot is only trained on GPT-4o best of 4 debates.
What does this mean? I would assume Elo needs to be computed by running a tournament between the models.
Cool! Nice to see more work on debate with some mild positive results. I didn’t read super closely but some quick thoughts.
apologies if I’m missing something but what do you mean by F1 in this case? do you mean positive = proposer / first speaker is correct, and negative = proposer / first speaker is incorrect? in prior work we just averaged between orderings in debate and used accuracy. consultancy and debate should both have a 50⁄50 prior so it’s fine. since we expect the model to agree with the proposer more in consultancy, it should bias towards positives. I worry that F1 could bias the results towards debate in this case, because F1 favors a classifier that’s more balanced, all else equal. Say it’s 50% positive in debate and 90% positive in consultancy but otherwise random. 50% positive random guesses = .5 F1, but 90% positive random guesses = .18 F1. Debate looks way better but actually both are random.
What were the accuracies?
hmm, this doesn’t sound like adversarial debate, it just sounds like a scaffolded grader… I’m curious what the logic was here. I understand that open consultancy seems like a more realistic baseline in some ways but I think for scalable oversight we really do care about and want to test the adversarial setting. (I might disagree with Zac on this as well.) Otherwise, I think we’re just playing around with scaffolding methods.
I wonder if things like the Tinker API would make it easier to do proper self-play RL experiments.