AI Custom Chatbots Cut Cognitive Load but Show No Clear Learning Gain — A University of Cologne Physics-Education RCT

Researchers in the Faculty of Mathematics and Natural Sciences at the University of Cologne, Germany, ran a randomized controlled study comparing AI-generated custom chatbot explanations against standard textbook material as supplementary support for physics learning.
The AI-chatbot condition produced statistically significant increases in positive-activating emotions, situational interest and self-efficacy, and significant reductions in both intrinsic and extraneous cognitive load, compared with the textbook condition. However, the authors explicitly report an indefinite effect on objective learning-outcome measures — the trial did not find a clear advantage for the chatbot condition on test performance.
Published in Physical Review Physics Education Research (2025), the study is an honest example of an AI tool improving how students feel about learning without yet demonstrating it improves what they learn; it was conducted in a single research setting and does not address data-protection or teacher-training questions.

Read the full analysis: https://journals.aps.org/prper/abstract/10.1103/PhysRevPhysEducRes.21.010147