{"id":1186331,"date":"2024-12-02T00:00:00","date_gmt":"2024-12-02T08:00:00","guid":{"rendered":"https:\/\/cm-edgetun.pages.dev\/en-us\/research\/?post_type=msr-research-item&#038;p=1186331"},"modified":"2026-09-15T15:50:23","modified_gmt":"2026-09-15T22:50:23","slug":"self-improvement-in-language-models-the-sharpening-mechanism","status":"publish","type":"msr-research-item","link":"https:\/\/cm-edgetun.pages.dev\/en-us\/research\/publication\/self-improvement-in-language-models-the-sharpening-mechanism\/","title":{"rendered":"Self-Improvement in Language Models: The Sharpening Mechanism"},"content":{"rendered":"\n\n\n<p class=\"wp-block-paragraph\">Recent work in language modeling has raised the possibility of self-improvement, where a language models evaluates and refines its own generations to achieve higher performance without external feedback. It is impossible for this self-improvement to create information that is not already in the model, so why should we expect that this will lead to improved capabilities? We offer a new perspective on the capabilities of self-improvement through a lens we refer to as sharpening. Motivated by the observation that language models are often better at verifying response quality than they are at generating correct responses, we formalize self-improvement as using the model itself as a verifier during post-training in order to &#8220;sharpen&#8221; the model to one placing large mass on high-quality sequences, thereby amortizing the expensive inference-time computation of generating good sequences. We begin by introducing a new statistical framework for sharpening in which the learner aims to sharpen a pre-trained base policy via sample access, and establish fundamental limits. Then we analyze two natural families of self-improvement algorithms based on SFT and RLHF. We find that (i) the SFT-based approach is minimax optimal whenever the initial model has sufficient coverage, but (ii) the RLHF-based approach can improve over SFT-based self-improvement by leveraging online exploration, bypassing the need for coverage. Finally, we empirically validate the sharpening mechanism via inference-time and amortization experiments. We view these findings as a starting point toward a foundational understanding that can guide the design and evaluation of self-improvement algorithms.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Recent work in language modeling has raised the possibility of self-improvement, where a language models evaluates and refines its own generations to achieve higher performance without external feedback. It is impossible for this self-improvement to create information that is not already in the model, so why should we expect that this will lead to improved [&hellip;]<\/p>\n","protected":false},"featured_media":0,"template":"","meta":{"msr-url-field":"","msr-podcast-episode":"","msrModifiedDate":"","msrModifiedDateEnabled":false,"ep_exclude_from_search":false,"_classifai_error":"","msr-author-ordering":[{"type":"text","value":"Audrey Huang","user_id":0},{"type":"user_nicename","value":"Adam Block","user_id":"43395"},{"type":"user_nicename","value":"Dylan Foster","user_id":"40330"},{"type":"text","value":"Dhruv Rohatgi","user_id":0},{"type":"user_nicename","value":"Cyril Zhang","user_id":"39829"},{"type":"text","value":"Max Simchowitz","user_id":0},{"type":"user_nicename","value":"Jordan Ash","user_id":"39826"},{"type":"user_nicename","value":"Akshay 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