Saved in:
Bibliographic Details
Main Authors: Friedman, Natalie, Nyanyo, Adelaide, Weatherwax, Kevin, Wang, Lifei, Zhu, Chengchao, Zhu, Zeshu, Mountford, S. Joy
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2603.06878
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911495241072640
author Friedman, Natalie
Nyanyo, Adelaide
Weatherwax, Kevin
Wang, Lifei
Zhu, Chengchao
Zhu, Zeshu
Mountford, S. Joy
author_facet Friedman, Natalie
Nyanyo, Adelaide
Weatherwax, Kevin
Wang, Lifei
Zhu, Chengchao
Zhu, Zeshu
Mountford, S. Joy
contents Large language models (LLMs) have become common decision-support tools across educational and professional contexts, raising questions about how their outputs shape human critical thinking. Prior work suggests that the amount of AI assistance can influence cognitive engagement, yet little is known about how specific properties of LLM outputs (e.g., response length) impacts users' critical evaluation of information. In this study, we examine whether the length of LLM responses shapes users' accuracy in evaluating LLM-generated reasoning on critical thinking tasks, particularly in interaction with the correctness of the LLM's reasoning. To begin evaluating this, we conducted a within-subjects experiment with 24 participants who completed 15 modified Watson--Glaser critical thinking items, each accompanied by an LLM-generated explanation that varied in length and correctness. Mixed-effects logistic regression revealed a strong and statistically reliable effect of LLM output correctness on participant accuracy, with participants more likely to answer correctly when the LLM's explanation was correct. Response length appeared to moderated this effect: when the LLM output was incorrect, medium-length explanations were associated with higher participant accuracy than either shorter or longer explanations, whereas accuracy remained high across lengths when the LLM output was correct. Together, these findings suggest that response length alone may be insufficient to support critical thinking, and that how reasoning is presented-including a potential advantage of mid-length explanations under some conditions-points to design opportunities for LLM-based decision-support systems that emphasize transparent reasoning and calibrated expressions of certainty.
format Preprint
id arxiv_https___arxiv_org_abs_2603_06878
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Not Too Short, Not Too Long: How LLM Response Length Shapes People's Critical Thinking in Error Detection
Friedman, Natalie
Nyanyo, Adelaide
Weatherwax, Kevin
Wang, Lifei
Zhu, Chengchao
Zhu, Zeshu
Mountford, S. Joy
Artificial Intelligence
Large language models (LLMs) have become common decision-support tools across educational and professional contexts, raising questions about how their outputs shape human critical thinking. Prior work suggests that the amount of AI assistance can influence cognitive engagement, yet little is known about how specific properties of LLM outputs (e.g., response length) impacts users' critical evaluation of information. In this study, we examine whether the length of LLM responses shapes users' accuracy in evaluating LLM-generated reasoning on critical thinking tasks, particularly in interaction with the correctness of the LLM's reasoning. To begin evaluating this, we conducted a within-subjects experiment with 24 participants who completed 15 modified Watson--Glaser critical thinking items, each accompanied by an LLM-generated explanation that varied in length and correctness. Mixed-effects logistic regression revealed a strong and statistically reliable effect of LLM output correctness on participant accuracy, with participants more likely to answer correctly when the LLM's explanation was correct. Response length appeared to moderated this effect: when the LLM output was incorrect, medium-length explanations were associated with higher participant accuracy than either shorter or longer explanations, whereas accuracy remained high across lengths when the LLM output was correct. Together, these findings suggest that response length alone may be insufficient to support critical thinking, and that how reasoning is presented-including a potential advantage of mid-length explanations under some conditions-points to design opportunities for LLM-based decision-support systems that emphasize transparent reasoning and calibrated expressions of certainty.
title Not Too Short, Not Too Long: How LLM Response Length Shapes People's Critical Thinking in Error Detection
topic Artificial Intelligence
url https://arxiv.org/abs/2603.06878