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Smaller, Weaker, yet Better: Training LLM Reasoners via Compute-Optimal Sampling (arxiv.org)
59 points by towaihee on Sep 3, 2024 | hide | past | pdf | 5 comments on HN

In plain words: A big expensive AI writes problems to train reasoners; this compares that with a smaller, cheaper AI under the same computing budget. Its problems covered more ground and were more varied, and models trained on them beat those trained on the expensive model's problems.

Abstract · Smaller, Weaker, Yet Better: Training LLM Reasoners via Compute-Optimal Sampling

Training on high-quality synthetic data from strong language models (LMs) is a common strategy to improve the reasoning performance of LMs. In this work, we revisit whether this strategy is compute-optimal under a fixed inference budget (e.g., FLOPs). To do so, we investigate the trade-offs between generating synthetic data using a stronger but more expensive (SE) model versus a weaker but cheaper (WC) model. We evaluate the generated data across three key metrics: coverage, diversity, and false positive rate, and show that the data from WC models may have higher coverage and diversity, but also exhibit higher false positive rates. We then finetune LMs on data from SE and WC models in different settings: knowledge distillation, self-improvement, and a novel weak-to-strong improvement setup where a weaker LM teaches reasoning to a stronger LM. Our findings reveal that models finetuned on WC-generated data consistently outperform those trained on SE-generated data across multiple benchmarks and multiple choices of WC and SE models. These results challenge the prevailing practice of relying on SE models for synthetic data generation, suggesting that WC may be the compute-optimal approach for training advanced LM reasoners.

Hritik Bansal, Arian Hosseini, Rishabh Agarwal, Vinh Q. Tran, Mehran Kazemi
arXiv:2408.16737 · cs.CL, cs.AI · submitted Aug 29, 2024 · updated Oct 7, 2024
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I found this to be the key quote:

> Since the 9B model is roughly 3 times smaller than the 27B model, at a fixed sampling compute budget we can sample 3× more sample solutions per problem for Gemma2-9B.

Essentially, training on samples from a weaker LLM is better than 1/3 the samples from a stronger LLM.

I find that researchers choices of names for the sake of differentiation is more of a barrier than something helpful. Sometimes it feels like I know nothing, but in reality it is the name of the "technique" or phenomena that does not get parsed by my brain.

Things like "Compute-Optimal Sampling" sound just like any other made up gibberish that may or may not exist. Wordings like "memory-centric subsampling", "search based hyper space modeling", "locally induced entropy optimization" don't get parsed. And more often than not after reading such papers, I've come to find out that it is a fancy name for something a toddler knows about. Really disappointing.

I see what you're saying, but I don't think it applies in this case. Correct use of jargon helps domain experts communicate with higher precision, and papers tend to be written by domain experts for consumption by other domain experts.

Of course there are some (possibly many!) papers where jargon is abused to make something sound smarter. Sometimes this can also happen unintentionally.

In this case, "compute-optimal X" is standard terminology used in large-scale ML model design for finding the most optimal tradeoff with regards to compute when trying to achieve X.

Here, the paper is about finding the optimal model size tradeoff when training on LLM-generated synthetic data. Imagine you have a class of LLMs, from small to infinitely large. The larger the LLM, the higher the quality of your synthetic data, but you will also spend more compute to generate this data ("sampling" the data). Smaller LLMs can generate more data with the same compute budget, but at worse quality.

The paper does some experiments to find that in their case, you don't always want the largest possible LLM for synthetic data (as previously thought by many practitioners), instead you can get further by making more calls to a smaller but worse LLM.

Just copy/paste it into chatgpt and ask it to use less jargon or similar.

You are never going to win the jargon battle. It is what it is. People wrap up entire concepts in a few words and hell if they can be bothered writing out the details of the concept over and over again.

I thought that the malpractice of starting bar graphs at non-zero values was reserved for dishonest publication formats such as news papers and CPU benchmarks. I did not expect that from a scientific paper by Google DeepMind.