Inference-Aware Prompt Optimization for Aligning Black-Box Large Language Models

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Mahmud, Saaduddin, Nakamura, Mason, Wray, Kyle Hollins, Zilberstein, Shlomo
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866912892463349760
author Mahmud, Saaduddin
Nakamura, Mason
Wray, Kyle Hollins
Zilberstein, Shlomo
author_facet Mahmud, Saaduddin
Nakamura, Mason
Wray, Kyle Hollins
Zilberstein, Shlomo
contents Prompt optimization methods have demonstrated significant effectiveness in aligning black-box large language models (LLMs). In parallel, inference scaling strategies such as Best-of-N Sampling and Majority Voting have likewise been shown to improve alignment and performance by trading additional computation for better output. However, existing prompt optimization approaches are inference strategy agnostic; that is, they optimize prompts without accounting for the inference strategy. This constitutes a significant methodological gap, as our empirical and theoretical analysis reveals a strong interdependence between these two paradigms. Moreover, we find that user preferences regarding trade-offs among multiple objectives and inference budgets substantially influence the choice of prompt and inference configuration. To address this gap, we introduce a novel unified framework named IAPO (Inference-Aware Prompt Optimization) that jointly optimizes the prompt and inference scale, while being aware of the inference budget and different task objectives. We then develop a fixed-budget training algorithm for IAPO, called PSST (Prompt Scaling via Sequential Trimming), and establish finite-budget guarantees on the error probability. Finally, we evaluate the effectiveness of PSST on six tasks, including multi-objective text generation and reasoning, and demonstrate the critical role of incorporating inference-awareness in aligning black-box LLMs using prompt optimization.
format Preprint
id arxiv_https___arxiv_org_abs_2508_10030
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Inference-Aware Prompt Optimization for Aligning Black-Box Large Language Models
Mahmud, Saaduddin
Nakamura, Mason
Wray, Kyle Hollins
Zilberstein, Shlomo
Computation and Language
Artificial Intelligence
Prompt optimization methods have demonstrated significant effectiveness in aligning black-box large language models (LLMs). In parallel, inference scaling strategies such as Best-of-N Sampling and Majority Voting have likewise been shown to improve alignment and performance by trading additional computation for better output. However, existing prompt optimization approaches are inference strategy agnostic; that is, they optimize prompts without accounting for the inference strategy. This constitutes a significant methodological gap, as our empirical and theoretical analysis reveals a strong interdependence between these two paradigms. Moreover, we find that user preferences regarding trade-offs among multiple objectives and inference budgets substantially influence the choice of prompt and inference configuration. To address this gap, we introduce a novel unified framework named IAPO (Inference-Aware Prompt Optimization) that jointly optimizes the prompt and inference scale, while being aware of the inference budget and different task objectives. We then develop a fixed-budget training algorithm for IAPO, called PSST (Prompt Scaling via Sequential Trimming), and establish finite-budget guarantees on the error probability. Finally, we evaluate the effectiveness of PSST on six tasks, including multi-objective text generation and reasoning, and demonstrate the critical role of incorporating inference-awareness in aligning black-box LLMs using prompt optimization.
title Inference-Aware Prompt Optimization for Aligning Black-Box Large Language Models
topic Computation and Language
Artificial Intelligence
url https://arxiv.org/abs/2508.10030