Computer science master’s student interested in AI and AI safety.
Stephen McAleese
Karma: 628
Regularize by a function other than KL divergence. For heavy-tailed error distributions, KL divergence doesn’t work, but capping the maximum odds ratio for any action (similar to quantilizers) still results in positive utility.
A recent paper from UC Berkeley named Preventing Reward Hacking with Occupancy Measure Regularization proposes replacing KL divergence regularization with occupancy measure (OM) regularization. OM regularization involves regularizing based on the state or state-action distribution rather than the the action distribution:
“Our insight is that when reward hacking, the agent visits drastically different states from those reached by the safe policy, causing large deviations in state occupancy measure (OM). Thus, we propose regularizing based on the OM divergence between policies instead of AD [action distribution] divergence to prevent reward hacking”
The idea is that regularizing to minimize changes in the action distribution isn’t always safe because small changes in the action distribution can cause large changes in the states visited by the agent:
Suppose we have access to a safe policy that drives slowly and avoids falling off the cliff. However, the car is optimizing a proxy reward function that prioritizes quickly reaching the destination, but not necessarily staying on the road. If we try to regularize the car’s action distributions to the safe policy, we will need to apply heavy regularization, since only slightly increasing the probability of some unsafe action (e.g., making a sharp right turn) can lead to disaster.
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Our proposal follows naturally from this observation: to avoid reward hacking, regularize based on divergence from the safe policy’s occupancy measure, rather than action distribution. A policy’s occupancy measure (OM) is the distribution of states or state-action pairs seen by a policy when it interacts with its environment.
I just asked GPT-4 a GSM8K problem and I agree with your point. I think what’s happening is that GPT-4 has been fine-tuned to respond with chain-of-thought reasoning by default so it’s no longer necessary to explicitly ask it to reason step-by-step. Though if you ask it to “respond with just a single number” to eliminate the chain-of-thought reasoning it’s problem-solving ability is much worse.
Chain-of-thought prompting makes models much more capable. In the original paper “Chain-of-Thought Prompting Elicits Reasoning in Large Language Models”, PaLM 540B with standard prompting only solves 18% of problems but 57% of problems with chain-of-thought prompting.
I expect the use of agent features such as reflection will lead to similar large increases in capabilities as well in the near future.
Currently, groups of LLM agents can collaborate using frameworks such as ChatDev, which simulates a virtual software company using LLM agents with different roles. Though I think human organizations are still more effective for now. For example, corporations such as Microsoft have over 200,000 employees and can work on multi-year projects. But it’s conceivable that in the future there could be virtual companies composed of millions of AIs that can coordinate effectively and can work continuously at superhuman speed for long periods of time.
I think I might create a new post using information from this post which covers the new AI alignment landscape.
I think this section of the post is slightly overstating the opportunity cost of doing a PhD. PhD students typically spend most of their time on research so ideally, they should be doing AI safety research during the PhD (e.g. like Stephen Casper). If the PhD is in an unrelated field or for the sake of upskilling then there is a more significant opportunity cost relative to working directly for an AI safety organization.
Thank you for explaining PPO. In the context of AI alignment, it may be worth understanding in detail because it’s the core algorithm at the heart of RLHF. I wonder if any of the specific implementation details of PPO or how it’s different from other RL algorithms have implications for AI alignment. To learn more about PPO and RLHF, I recommend reading this paper: Secrets of RLHF in Large Language Models Part I: PPO.
LLMs aren’t that useful for alignment experts because it’s a highly specialized field and there isn’t much relevant training data. The AI Safety Chatbot partially solves this problem using retrieval-augmented generation (RAG) on a database of articles from https://aisafety.info. There also seem to be plans to fine-tune it on a dataset of alignment articles.
OP says that this post is focused on RL policy gradient algorithms (e.g. PPO) where the RL signal is used by gradient descent to update the policy.
But what about Q-learning which is another popular RL algorithm? My understanding of Q-learning is that the policy network takes an observation as input, calculates the value (expected return) of each possible action in the state and then chooses the action with the highest value.
Does this mean that reward is not the optimization target for policy gradient algorithms but is for Q-learning algorithms?
I agree. GPT-4 is an AGI for the kinds of tasks I care about such as programming and writing. ChatGPT4 in its current form (with the ability to write and execute code) seems to be at the expert human level in many technical and quantitative subjects such as statistics and programming.
For example, last year I was amazed when I gave ChatGPT4 one of my statistics past exam papers and it got all the questions right except for one which involved interpreting an image of a linear regression graph. The questions typically involve understanding the question, thinking of an appropriate statistical method, and doing calculations to find the right answer. Here’s an example question:
Times (in minutes) for a sample of 8 players are presented in Table 1 below. Using an appropriate test at the 5% significance level, investigate whether there is evidence of a decrease in the players’ mean 5k time after the six weeks of training. State clearly your assumptions and conclusions, and report a p-value for your test statistic.
The solution to this question is a paired sample t-test.
Sure, GPT-4 has probably seen similar questions before but so do students since they can practice past papers.
This year, one of my professors designed his optimization assignment to be ChatGPT-proof but I found that it could still solve five out of six questions successfully. The questions involved converting natural language descriptions of optimization problems into mathematical formulations and solving them with a program.
One of the few times I’ve seen GPT-4 genuinely struggle to do a task is when I asked it to solve a variant of the Zebra Puzzle which is a challenging logical reasoning puzzle that involves updating a table based on limited information and using logical reasoning and a process of elimination to find the correct answer.
I wrote a blog post on whether AI alignment can be automated last year. The key takeaways:
There’s a chicken-and-egg problem where you need the automated alignment researcher to create the alignment solution but the alignment solution is needed before you can safely create the automated alignment researcher. The solution to this dilemma is an iterative bootstrapping process where the AI’s capabilities and alignment iteratively improve each other (a more aligned AI can be made more capable and a more capable AI can create a more aligned AI and so on).
Creating the automated alignment researcher only makes sense if it is less capable and general than a full-blown AGI. Otherwise, aligning it is just as hard as aligning AGI.
There’s no clear answer to this question because it depends on your definition of “AI alignment” work. Some AI alignment work is already automated today such as generating datasets for evals, RL from AI feedback, and simple coding work. On the other hand, there are probably some AI alignment tasks that are AGI-complete such as deep, cross-domain, and highly creative alignment work.
The idea of the bootstrapping strategy is that as the automated alignment researcher is made more capable, it improves its own alignment strategies which enables further capability and alignment capabilities and so on. So hopefully there is a virtuous feedback loop over time where more and more alignment tasks are automated.
However, this strategy relies on a robust feedback loop which could break down if the AI is deceptive, incorrigible, or undergoes recursive self-improvement and I think these risks increase with higher levels of capability.
I can’t find the source but I remember reading somewhere on the MIRI website that MIRI aims to do work that can’t easily be automated so Eliezer’s pessimism makes sense in light of that information.
Further reading:
Strong upvote. I think this is an excellent, carefully written, and timely post. Explaining issues that may arise from current alignment methods is urgent and important. It provides a good explanation of the unidentifiability or inner alignment problem that could arise from advanced AIs systems trained with current behavioral safety methods. It also highlights the difficulty of making AIs that can automate alignment research which is part of OpenAI’s current plan. I also liked the in-depth description of what advanced science AIs would be capable of as well as the difficulty of keeping humans in the loop.
Nice post! The part I found most striking was how you were able to use the mean difference between outputs on harmful and harmless prompts to steer the model into refusing or not. I also like the refusal metric which is simple to calculate but still very informative.
TL;DR: Private AI companies such as Anthropic which have revenue-generating products and also invest heavily in AI safety seem like the best type of organization for doing AI safety research today. This is not the best option in an ideal world and maybe not in the future but right now I think it is.
I appreciate the idealism and I’m sure there is some possible universe where shutting down these labs would make sense but I’m quite unsure about whether doing so would actually be net-beneficial in our world and I think there’s a good chance it would be net-negative in reality.
The most glaring constraint is finances. AI safety is funding-constrained so this is worth mentioning. Companies like DeepMind and OpenAI spend hundreds of millions of dollars per year on staff and compute and I doubt that would be possible in a non-profit. Most of the non-profits working on AI safety (e.g. Redwood Research) are small with just a handful of people. OpenAI changed their company from a non-profit to a capped for-profit because they realized that being a non-profit would have been insufficient for scaling their company and spending. OpenAI now generates $1 billion in revenue and I think it’s pretty implausible that a non-profit could generate that amount of income.
The other alternative apart from for-profit companies and philanthropic donations is government funding. It is true that governments fund a lot of science. For example, the US government funds 40% of basic science research. And a lot of successful big science projects such as CERN and the ITER fusion project seem to be mostly government-funded. However, I would expect a lot of government-funded academic AI safety grants to be wasted by professors skilled at putting “AI safety” in their grant applications so that they can fund whatever they were going to work on anyway. Also, the fact that the US government has secured voluntary commitments from AI labs to build AI safely gives me the impression that governments are either unwilling or incapable of working on AI safety and instead would prefer to delegate it to private companies. On the other hand, the UK has a new AI safety institute and a language model task force.
Another key point is research quality. In my opinion, the best AI safety research is done by the big labs. For example, Anthropic created constitutional AI and they also seem to be a leader in interpretability research. I think empirical AI safety work and AI capabilities work involve very similar skills (coding etc.) and therefore it’s not surprising that leading AI labs also do the best empirical AI safety work. There are several other reasons for explaining why big AI labs do the best empirical AI safety work. One is talent. Top labs have the money to pay high salaries which attracts top talent. Work in big labs also seems more collaborative than in academia which seems important for large projects. Many top projects have dozens of authors (e.g. the Llama 2 paper). Finally, there is compute. Right now, only big labs have the infrastructure necessary to do experiments on leading models. Doing experiments such as fine-tuning large models requires a lot of money and hardware. For example, this paper by DeepMind on reducing sycophancy apparently involved fine-tuning the 540B PaLM model which is probably not possible for most independent and academic researchers right now and consequently, they usually have to work with smaller models such as Llama-2-7b. However, the UK is investing in some new public AI supercomputers which hopefully will level the playing field somewhat. If you think theoretical work (e.g. agent foundations) is more important than empirical work then big labs have less of an advantage. Though DeepMind is doing some of that too.
GPT-4 is the model that has been trained with the most training compute which suggests that compute is the most important factor for capabilities. If that wasn’t true, we would see some other company training models with more compute but worse performance which doesn’t seem to be happening.
No offense but I sense status quo bias in this post.
If you replace “AI” with “industrial revolution” I don’t think the meaning of the text changes much and I expect most people would rather live today than in the Middle Ages.
One thing that might be concerning is that older generations (us in the future) might not have the ability to adapt to a drastically different world in the same way that some old people today struggle to use the internet.
I personally don’t expect to be overly nostalgic in the future because I’m not that impressed by the current state of the world: factory farming, the hedonic treadmill, physical and mental illness, wage slavery, aging, and ignorance are all problems that I hope are solved in the future.
Although AI progress is occurring gradually right now where regulation can keep up, I do think a hard takeoff is still a possibility.
My understanding is that fast recursive self-improvement occurs once there is a closed loop of fully autonomous self-improving AI. AI is not capable enough for that yet and most of the important aspects of AI research are still done by humans but it could become a possibility in the future once AI agents are advanced and reliable enough.
In the future before an intelligence explosion, there could be a lot of regulation and awareness of AI relative to today. But if there’s a fast takeoff, regulation would be unable to keep up with AI progress.
Recently I learned that the negative effect of sleep deprivation on cognitive performance seems to accumulate over several days. Five days of insufficient sleep can lower cognitive performance by up to 15 IQ points according to this source.
State-of-the-art models such as Gemini aren’t LLMs anymore. They are natively multimodal or omni-modal transformer models that can process text, images, speech and video. These models seem to me like a huge jump in capabilities over text-only LLMs like GPT-3.