Interpreting and Controlling Model Behavior via Constitutions for Atomic Concept Edits
Neha Kalibhat, Zi Wang, Prasoon Bajpai, Drew Proud, Wenjun Zeng, Been Kim, Mani Malek
TL;DR
This work tackles the challenge of interpreting and controlling black-box generative models by learning a natural language constitution that maps atomic concept edits (ACEs) to predictable behavioral changes. The authors formalize ACEs as add, remove, or replace operations on prompt concepts and optimize constitutions via a surrogate LLM and an evolutionary process to guide ACE generation. They demonstrate the approach on Word Count, Math, and text-to-image alignment tasks, using diverse models and autoraters, and show that constitution-guided ACE achieves about 1.86x higher success rates than non-constitution baselines while preserving prompt diversity. The framework yields actionable, generalizable insights into how prompting concepts shape model outputs and enables more efficient, interpretable steering across modalities, with potential extensions to broader inputs and operator spaces.
Abstract
We introduce a black-box interpretability framework that learns a verifiable constitution: a natural language summary of how changes to a prompt affect a model's specific behavior, such as its alignment, correctness, or adherence to constraints. Our method leverages atomic concept edits (ACEs), which are targeted operations that add, remove, or replace an interpretable concept in the input prompt. By systematically applying ACEs and observing the resulting effects on model behavior across various tasks, our framework learns a causal mapping from edits to predictable outcomes. This learned constitution provides deep, generalizable insights into the model. Empirically, we validate our approach across diverse tasks, including mathematical reasoning and text-to-image alignment, for controlling and understanding model behavior. We found that for text-to-image generation, GPT-Image tends to focus on grammatical adherence, while Imagen 4 prioritizes atmospheric coherence. In mathematical reasoning, distractor variables confuse GPT-5 but leave Gemini 2.5 models and o4-mini largely unaffected. Moreover, our results show that the learned constitutions are highly effective for controlling model behavior, achieving an average of 1.86 times boost in success rate over methods that do not use constitutions.
