Hostname: page-component-76d6cb85b7-8p85h Total loading time: 0 Render date: 2026-07-10T19:31:23.340Z Has data issue: false hasContentIssue false

Evaluating the performance of large language models in taxonomic classification of questions in verbal protocols of design

Published online by Cambridge University Press:  02 April 2026

Ahmed Shahriar Sakib
Affiliation:
Management Science and Engineering, Faculty of Engineering, University of Waterloo, Waterloo, Ontario, Canada
Ada Hurst*
Affiliation:
Management Science and Engineering, Faculty of Engineering, University of Waterloo, Waterloo, Ontario, Canada
Frank Safayeni
Affiliation:
Management Science and Engineering, Faculty of Engineering, University of Waterloo, Waterloo, Ontario, Canada
*
Corresponding author: Ada Hurst; Email: adahurst@uwaterloo.ca
Rights & Permissions [Opens in a new window]

Abstract

This study investigates the use of large language models (LLMs) to classify question utterances within verbal design protocols according to Eris’ (2004) taxonomy. We evaluate the performance of two proprietary LLMs – OpenAI’s GPT-4.1 and Anthropic’s Claude Sonnet 4.5 – across experiments designed to assess classification accuracy, sensitivity to prompt configuration and in-context learning (ICL), and generalization across datasets and models. Using two human-coded datasets of differing size and quality, we measure alignment between LLM-generated labels and human judgments at both question category and subcategory levels. Results show that both LLMs achieved moderate to strong alignment rates at the category level (up to 85.7% for GPT-4.1 and 82.9% for Claude Sonnet 4.5), with substantially lower alignment at the more granular subcategory level. Performance differences across prompt configurations and ICL conditions were small, indicating robust generalization across datasets and transferability of prompt designs. While these results suggest that LLMs can effectively support scalable question classification, human judgment and oversight remain essential. Future research should explore the development and evaluation of alternative hybrid human–LLM workflows in protocol analysis, as well as the use of smaller or open-source models to address data privacy concerns.

Information

Type
Research Article
Creative Commons
Creative Common License - CCCreative Common License - BY
This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited.
Copyright
© The Author(s), 2026. Published by Cambridge University Press
Figure 0

Table 1. Question categories and subcategories according to Eris’ (2004) taxonomy

Figure 1

Table 2. Examples of design research studies using Eris’ (2004) taxonomy

Figure 2

Table 3. GPT-4.1 classification performance across different prompt configurations. Includes references to appendices with full prompts

Figure 3

Table 4. Alignment metrics for GPT-4.1 computed at the category and subcategory levels, benchmarked against human inter-rater agreement

Figure 4

Table 5. Confusion matrix for question categorization at the category level – instances (proportion of total). Prompt configuration according to Condition G

Figure 5

Table 6. Experiment 2 results: Alignment metrics for GPT-4.1 across each question subcategory

Figure 6

Table 7. Confusion matrix at the subcategory level – dataset d1, prompt configuration of Condition G

Figure 7

Table 8. Human–LLM alignment – Accuracy (%) [95% CI]; κ [95% CI] – across LLMs and ICL/test pair conditions

Figure 8

Table 9. LLM provider API configurations and pricing assumptions