Evaluating the Smooth Control of Attribute Intensity in Text Generation with LLMs
Shang Zhou, Feng Yao, Chengyu Dong, Zihan Wang, Jingbo Shang
TL;DR
This work tackles the problem of smoothly controlling attribute intensity in text generated by large language models. It defines smooth controllable text generation (SCTG), introduces an automatic evaluation pipeline based on Elo ratings and GPT-4 judgments, and builds a 1,500-query benchmark across five attributes. It compares two training-free methods—prompting with semantic shifters and Representation Engineering (RepE)—across multiple models, finding that prompting is often nearly as effective as RepE and that larger model sizes can hinder smooth control. The framework and findings provide practical guidance for deploying finely calibrated attribute control in real-world LLM applications and establish a scalable evaluation toolkit for SCTG.
Abstract
Controlling the attribute intensity of text generation is crucial across scenarios (e.g., writing conciseness, chatting emotion, and explanation clarity). The remarkable capabilities of large language models (LLMs) have revolutionized text generation, prompting us to explore such \emph{smooth control} of LLM generation. Specifically, we propose metrics to assess the range, calibration, and consistency of the generated text's attribute intensity in response to varying control values, as well as its relevance to the intended context. To quantify the attribute intensity and context relevance, we propose an effective evaluation framework leveraging the Elo rating system and GPT4, both renowned for their robust alignment with human judgment. We look into two viable training-free methods for achieving smooth control of LLMs: (1) Prompting with semantic shifters, and (2) Modifying internal model representations. The evaluations of these two methods are conducted on $5$ different attributes with various models. Our code and dataset can be obtained from \url{https://github.com/ShangDataLab/Smooth-Control}.
