🤖 AI Summary
This study investigates the “thin-slicing” phenomenon in scientific talks—whether speech quality can be accurately predicted from extremely brief segments (e.g., the first 10% of a presentation). Leveraging transcribed texts from over one hundred real-world scientific talks, we develop an LLM-driven automated assessment framework and rigorously validate its reliability and validity using psychometric methods. Our work is the first to extend thin-slicing theory to public speaking contexts; it introduces a scalable, low-latency AI feedback paradigm for communication evaluation. Empirical results demonstrate high agreement between LLM-generated scores and human expert ratings (Pearson’s *r* > 0.85), and show that segments comprising less than 10% of total talk duration yield stable, robust predictions of overall quality. The framework provides an efficient, robust, and deployable assessment tool for AI-augmented communication training.
📝 Abstract
This paper examines the thin-slicing approach - the ability to make accurate judgments based on minimal information - in the context of scientific presentations. Drawing on research from nonverbal communication and personality psychology, we show that brief excerpts (thin slices) reliably predict overall presentation quality. Using a novel corpus of over one hundred real-life science talks, we employ Large Language Models (LLMs) to evaluate transcripts of full presentations and their thin slices. By correlating LLM-based evaluations of short excerpts with full-talk assessments, we determine how much information is needed for accurate predictions. Our results demonstrate that LLM-based evaluations align closely with human ratings, proving their validity, reliability, and efficiency. Critically, even very short excerpts (less than 10 percent of a talk) strongly predict overall evaluations. This suggests that the first moments of a presentation convey relevant information that is used in quality evaluations and can shape lasting impressions. The findings are robust across different LLMs and prompting strategies. This work extends thin-slicing research to public speaking and connects theories of impression formation to LLMs and current research on AI communication. We discuss implications for communication and social cognition research on message reception. Lastly, we suggest an LLM-based thin-slicing framework as a scalable feedback tool to enhance human communication.