Measuring Psychological Depth in Language Models
Fabrice Y. Harel-Canada, Hanyu Zhou, Sreya Muppalla, Zeynep Senahan Yildiz, Miryung Kim, Amit Sahai, and Nanyun Peng, in Proceedings of The 2024 Conference on Empirical Methods in Natural Language Processing (EMNLP), 2024.
🏆 Outstanding Paper Award (<0.4%)
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Abstract
Evaluations of creative stories generated by large language models (LLMs) often focus on objective properties of the text, such as its style, coherence, and diversity. While these metrics are indispensable, they do not speak to a story’s subjective, psychological impact from a reader’s perspective. We introduce the Psychological Depth Scale (PDS), a novel framework rooted in literary theory that measures an LLM’s ability to produce authentic and narratively complex stories that provoke emotion, empathy, and engagement. We empirically validate our framework by showing that humans can consistently evaluate stories based on PDS (0.72 Krippendorff’s alpha). We also explore techniques for automating the PDS to easily scale future analyses. GPT-4o, combined with a novel Mixture-of-Personas (MoP) prompting strategy, achieves an average Spearman correlation of 0.51 with human judgment while Llama-3-70B with constrained decoding scores as high as 0.68 for empathy. Finally, we compared the depth of stories authored by both humans and LLMs. Surprisingly, GPT-4 stories either surpassed or were statistically indistinguishable from highly-rated human-written stories sourced from Reddit. By shifting the focus from text to reader, the Psychological Depth Scale is a validated, automated, and systematic means of measuring the capacity of LLMs to connect with humans through the stories they tell.
Bib Entry
@inproceedings{harel2024measuring,
author = {Harel-Canada, Fabrice Y and Zhou, Hanyu and Muppalla, Sreya and Yildiz, Zeynep Senahan and Kim, Miryung and Sahai, Amit and Peng, Nanyun},
title = {Measuring Psychological Depth in Language Models},
booktitle = {Proceedings of The 2024 Conference on Empirical Methods in Natural Language Processing (EMNLP)},
year = {2024}
}