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I think KL/entropy regularization is usually used to prevent mode collapse partly because it has nice theoretical properties. In particular, it is easy to reason about the optimal policy for the regularized objective - see for example the analysis in the paper Equivalence Between Policy Gradients and Soft Q-Learning.
Nevertheless, action-dependent baselines do appear in the literature, although the story is a bit confusing. This is my understanding of it from some old notes:
- The idea was explored in Q-Prop. But unlike you, their intention was not to change the optimal policy, but rather to reduce the variance of the policy gradient. Therefore they also incorporated an additional term to cancel out the bias introduced by the action-dependent baseline. (Incidentally, perhaps this analysis is also relevant to understanding ACTDE.)
- Later, The Mirage of Action-Dependent Baselines showed that in fact the variance reduction due the action-dependent baseline was negligible, and the entire benefit of Q-Prop was essentially due to a bug! The implementation normalized advantage estimates, but failed to apply the same adjustment to the bias-correction term, which turned out to be independently helpful because it's essentially the DDPG training objective.
We will do our best to fairly consider all applications, but realistically there is probably a small advantage to applying earlier. This is simply because there is a limit to how quickly we can grow the organization, so if hiring goes better than expected then it will be longer before we can take on even more people. With that being said, we do not have a fixed number of positions that we are hiring for; rather, we plan to vary the number of hires we make based on the strength of the applications we receive. Moreover, if we were unable to hire someone due to capacity constraints, we would very likely be interested in hiring them at a later date. For these reasons, I think the advantage to applying earlier is a fairly small consideration overall, and it sounds like it would make more sense for you to apply whenever you are comfortable.
1The questions on the take-home test vary in difficulty but are generally easier than olympiad problems, and should be accessible to graduates with relevant background. However, it is important to note that we are ultimately interested in research ability rather than the ability to solve self-contained problems under timed conditions. So although the take-home test forms part of our assessment, we also look at other signals such as research track-record (while recognizing that assessing research ability is unfortunately very hard).
(Note: I am talking about the current version of the test, it's possible that the difficulty will change as we refine our interview process.)
I think the kind of mathematical problem solving we're engaged in is common across theoretical physics (although this is just my impression as a non-physicist). I've noticed that some specific topics that have come up (such as Gaussian integrals and permanents) also crop up in quantum field theory, but I don't think that's a strong reason to prefer that background particularly. Broad areas that often come up include probability theory, computational complexity and discrete math, but it's not necessary to have a lot of experience in those areas, only to be able to pick things up from them as needed.
It's not quite this simple, the same issue arises if every PSD completion of the known-diagonal minor has zero determinant (e.g. ((?, 1, 2), (1, 1, 1), (2, 1, 1))). But I think in that case making the remaining diagonal entries large enough still makes the eigenvalues at least −ε, which is good enough.
I think the examples you give are valid, but there are several reasons why I think the situation is somewhat contingent or otherwise less bleak than you do:
- Counterexamples: I think there are research agendas that are less pre-paradigmatic than the ones you're focused on that are significantly more (albeit not entirely) parallelizable. For example, mechanistic interpretability and scalable oversight both have multiple groups focused on them and have grown substantially over the last couple of years. I'm aware that we disagree about how valuable these directions are.
- Survival of the fittest: Unfortunately I think in cases where an individual has been pursuing a research direction for many years and has tried but failed to get anyone else on board with it, there is some explanatory power to the hypothesis that the direction is not that productive. Note that I'm not claiming to have a strong view on any particular agenda, and there are of course other possibilities in any given case. On the flip side, I expect promising directions to gain momentum over time, even if only gradually, and I consider the counterexamples from point 1 to be instances of this effect.
- Fixable coordination/deference failures: I think it would be a mistake for absolutely everyone to go off and try to develop their own alignment strategy from scratch, and it's plausible that the group you're focused on is erring too far in this direction. My own strategy has been to do my best to develop my own inside view (which I think is important for research prioritization and motivation as well from a group epistemics perspective), use this to narrow down my set of options to agendas I consider plausible, but be considerably more willing to defer when it comes to making a final call about which agenda to pursue.
- Clarity from AI advances: If the risk from AI is real, then I expect the picture of it to become clearer over time as AI improves. As a consequence, it should become clearer to people which directions are worth pursuing, and theoretical approaches should evolve into practical ones than can be iterated on empirically. This should both cause the field to grow and lead to more parallelizable work. I think this is already happening, and even the public at large is picking up on the spookiness of current alignment failures (even though the discourse is unsurprisingly very muddled).
You might find this work interesting, which takes some small steps in this direction. It studies the effect of horizon length inasmuch as it makes credit assignment harder, showing that the number of samples required is an affine function of horizon length in a toy context.
I think the direction depends on what your expectations were – I'll try to explain.
First, some terminology: the term "horizon length" is used in the paper to refer to the number of timesteps over which the algorithm pays attention to rewards, as governed by the discount rate. In the biological anchors framework, the term "effective horizon length" is used to refer to a multiplier on the number of samples required to train the model, which is influenced by the horizon length and other factors. For clarity, I'll using the term "scaling multiplier" instead of "effective horizon length" in this comment. The paper studies the effect of the horizon length on the scaling multiplier in a toy MNIST setting.
One key takeaway is that the scaling multiplier is not simply proportional to the horizon length, as one might have naively expected. Instead, the number of samples required is the sum of two components, one that is inherent to the task and independent of the horizon length, and one that is proportional to the horizon length. Compared to the naive expectation, this means that training compute requirements are lower. On the other hand, this ignores reward sparsity, so you might expect training compute requirements to be higher once both horizon length and reward sparsity are accounted for.
The paper also lends some support to the modeling assumptions of the neural network anchor, by validating the hypotheses that (a) training compute requirements still scale as a power law in model size for reinforcement learning, and with a similar exponent, and (b) the scaling multiplier can indeed vary a lot between environments. This might make you put more weight on the neural network anchor, which could again have either directional effect.
The other takeaways are more methodological and I don't think have much of a directional effect.
I would wildly speculate that "simply" scaling up RLHF ~100x, while paying careful attention to rewarding models appropriately (which may entail modifying the usual training setup, as discussed in this comment), would be plenty to get current models to express calibrated uncertainty well. However:
- In practice, I think we'll make a lot of progress in the short term without needing to scale up this much by using various additional techniques, some that are more like "tricks" (e.g. teaching the model to generally express uncertainty when answering hard math problems) and some more principled (e.g. automating parts of the evaluation).
- Even ~100x is still much less than pre-training (e.g. WebGPT used ~20k binary comparisons, compared to ~300b pre-training tokens for GPT-3). The difficulty of course is that higher-quality data is more expensive to collect. However, most of the cost of RLHF is currently employee hours and compute, so scaling up data collection ~100x might not be as expensive as it sounds (although it would of course be a challenge to maintain data quality at this scale).
- Even though scaling up data collection will help, I think it's more important for labs to be prioritizing data quality (i.e. "reducing bias" rather than "reducing variance"): data quality issues are in some sense "scarier" in the long run, since they lead to the model systematically doing the wrong thing (e.g. deceiving the evaluators) rather than defaulting to the "safer" imitative pre-training behavior.
- It's pretty unclear how this picture will evolve over time. In the long run, we may end up needing much less extremely high-quality data, since larger pre-trained models are more sample efficient, and we may get better at using techniques like automating parts of the evaluation. I've written more about this question here, and I'd be excited to see more people thinking about it.
In short, sample efficiency is a problem right now, but not the only problem, and it's unclear how much longer it will continue to be a problem for.
Since this post was written, OpenAI has done much more to communicate its overall approach to safety, making this post somewhat obsolete. At the time, I think it conveyed some useful information, although it was perceived as more defensive than I intended.
My main regret is bringing up the Anthropic split, since I was not able to do justice to the topic. I was trying to communicate that OpenAI maintained its alignment research capacity, but should have made that point without mentioning Anthropic.
Ultimately I think the post was mostly useful for sparking some interesting discussion in the comments.