An Experimental Design Framework for Label-Efficient Supervised Finetuning of Large Language Models
(2401.06692)Abstract
Supervised finetuning (SFT) on instruction datasets has played a crucial role in achieving the remarkable zero-shot generalization capabilities observed in modern LLMs. However, the annotation efforts required to produce high quality responses for instructions are becoming prohibitively expensive, especially as the number of tasks spanned by instruction datasets continues to increase. Active learning is effective in identifying useful subsets of samples to annotate from an unlabeled pool, but its high computational cost remains a barrier to its widespread applicability in the context of LLMs. To mitigate the annotation cost of SFT and circumvent the computational bottlenecks of active learning, we propose using experimental design. Experimental design techniques select the most informative samples to label, and typically maximize some notion of uncertainty and/or diversity. In our work, we implement a framework that evaluates several existing and novel experimental design techniques and find that these methods consistently yield significant gains in label efficiency with little computational overhead. On generative tasks, our methods achieve the same generalization performance with only $50\%$ of annotation cost required by random sampling.
Overview
-
The paper introduces the use of experimental design as a label-efficient method to supervise fine-tuning of LLMs, which can be expensive with traditional active learning methods.
-
The novel strategies of 'maximum token uncertainty' and facility location function contribute to a more data-efficient fine-tuning process.
-
Experimental design selects informative samples based on measures of uncertainty and diversity without the computational costs of active learning.
-
The paper's proposed framework demonstrates that their experimental design strategies can cut annotation costs by half while maintaining model performance.
-
The study's results suggest a potential shift in LLM training towards cost-effective and computationally efficient practices, important for the technology's widespread adoption.
Introduction to Experimental Design in LLM Fine-tuning
Supervised fine-tuning (SFT) using instruction datasets is a powerful way to enhance the performance of LLMs. Instruction datasets are collections of natural language prompts paired with expert-generated responses that help LLMs learn to generalize across different tasks. The challenge, however, is that creating these datasets is costly - requiring substantial annotation efforts by human experts. To address this issue, traditional methods such as active learning have been considered, but they come with computational complexity that makes them less feasible for large-scale LLMs. The innovation presented in this paper is the application of experimental design to SFT, with a specific emphasis on label efficiency and reduced computational costs.
Moving Beyond Active Learning
Active learning has traditionally been the go-to approach for label-efficient model training. By iteratively training a model and using it to select informative samples for labeling, active learning aims to reduce the number of annotations required. Yet, when dealing with LLMs, the computational resources necessary for the repeated training cycles and inferences become a substantial barrier, calling for a more efficient alternative.
Experimental Design as a Solution
Experimental design is a methodology that organizes an experiment to gain information about an object of interest—in this case, determining the best subset of unlabeled examples for optimizing an AI system's performance. By selecting a representative set of prompts for annotation in one step prior to any labeling, experimental design bypasses much of the computational expense associated with active learning. This selection process relies on measures that reflect both uncertainty and the diversity of the unlabeled data, enabling a data-efficient way to fine-tune an LLM.
Implementation and Impact
The researchers tested several experimental design strategies, some of which are unique to this study, such as the "maximum token uncertainty" and the use of the facility location function to ensure diversity among selected samples. These novel strategies were evaluated within a tailored framework, and the results showed that their techniques improve label efficiency considerably. Indeed, the paper states that their methods can achieve the desired model performance with only half the annotation budget traditionally required by random sampling techniques.
The findings of this study suggest a promising new direction for training LLMs, where both accuracy and computational efficiency are paramount. As the need to fine-tune LLMs across increasing numbers of tasks grows, experimental design might present the balance between performance and cost-efficiency that is vital for the broader adoption and application of these sophisticated models. Future research may likely expand on these initial findings, refining the experimental design approaches further and exploring their integration with existing and novel fine-tuning methodologies.
Create an account to read this summary for free: