Open source inference time compute example from HuggingFace (opens in new tab)

Great work! When I use models like o1, they work better than sonnet and 4o for tasks that require some thinking but the output is often very verbose. Is it possible to get the best of both worlds? The thinking takes place resulting in better performance but the output is straightforward to work with like with sonnet and 4o. Did you observe similar behaviour with the 1B and 3B models? How does the model behaviour change when used for normal tasks that don't require thinking?

Also how well do these models work to extract structured output? Eg- perform ocr on some hand written text with math, convert to html and format formulas correctly etc. Single shot prompting doesn't work well with such problems but splitting the steps into consecutive api calls works well.

The big question is whether or not o3 is using any type of “meta-generation” algorithm at inference time, I.e are there multiple invocations of the LLM generation at all, or does it generate an insanely long reasoning trace in a single autoregressive stream that some somehow implicitly has search-like behavior? In other words, is the search-like behavior learned entirely in post-training and only implicitly exhibited at inference time, or is it explicitly done at inference time?

Given the enormous compute costs of o3, my speculation has been that search is explicit, but I’ve seen this post from Nathan Lambert for example that speculates (in the context of o1) that it’s possible for search to be entirely “baked-into” a single single stream roll-out (which would depend on significant long-context innovations):

https://www.interconnects.ai/p/openais-o1-using-search-was-a...

If true this would be extremely interesting.

In the blog post, learned verifiers are mentioned. Are these learned offline using data, and is the intent to learn a scoring heuristic to help the search?

Excellent and interesting post!

Minor gripe - The best-of-n | beam search illustration is not compatible with red-green color blindness. I can literally not see the difference between the Rejected and the Selected dots even if I zoom in.

I believe this is a valid point: HF's replication indeed uses larger off-the-shelf model as a verifier.

In contrast, in the original paper, verifier is a fine-tune of the exact same base model which is used to sample step-by-step solutions (="solver").

For problems that require multi-step reasoning, standard LLMs seem to be stuck. The field is increasingly interested in models like o1 that output many "guesses" to find the right one. Currently open-source does not know how to do this, but we are reimplementing several possible directions to try. This replicates one important path using search and a verifier model.

To spend more compute at inference time, at least two simple approaches are readily available:

1) make model output a full solution, step-by-step, then induce it to revise the solution - repeat this as many times as you have token-budget for. You can do this via prompting alone (see Reflexion for example), or you can fine-tune the model to do that. The paper explores fine-tuning of the base model to turn it into self-revision model.

2) sample step-by-step (one "thought"-sentence per line) solutions from the model, and do it at non-zero temperature to be able to sample multiple next-steps. Then use verifier model to choose between next-step candidates and prefer to continue the rollout of the more promising branches of "thoughts". There are many many methods of exploring such tree when you can score intermediate nodes (beam search is an almost 50 years old algorithm!).

If I understand correctly, Hugging Face is exploring approaches to tuning the output quality of a given model by tuning how long to let it run.

Normally when you run an LLM, you set your prompt and whatever tunable parameters, and the LLM software (eg. lamma.cpp) spits out tokens at whatever rate it can. If you want higher quality, you run a bigger model (though you're limited by the amount of memory you have available). If you want higher speed, you run a smaller model. Hugging Face seems to be looking at ways to make this tradeoff without switching between different models.