Reconceptualizing geometry learning in teacher education: The role of AI-based digital books in developing spatial literacy and conceptual understanding

<ns5:p>The development of Artificial Intelligence (AI) has transformed student interactions with digital learning resources, particularly in mathematics education. This study examined the effect of an AI-based digital textbook on spatial literacy and geometry understanding among 45 student teachers (M ± SD = 20.0 ± 0.9) using a quasi-experimental design over 7 weeks. Students learned geometry using a smart e-book, and spatial literacy was measured through visualization, reasoning, and communication. Data analysis used the Wilcoxon signed-rank test and normalized gain (N-gain). Results showed significant improvements in all dimensions of spatial literacy (p &lt; 0.05) with large effect sizes (r = 0.74–0.86). The average N-gain of 0.78 (&gt;0.70) is considered high. The greatest improvement was in the reasoning dimension, reflecting higher-order thinking and problem-solving skills, while spatial communication improved, emphasizing the systematic representation of ideas. These findings confirm that AI can deliver adaptive, interactive, and contextual learning experiences more effectively than conventional e-books and support the internalization of geometry concepts. Scientifically and practically, AI-powered digital textbooks expand the mathematics education literature, support STEM curriculum development, improve teaching quality, and reduce the spatial literacy gap. This research opens the door to more complex adaptive AI development, multimodality integration, and longitudinal studies to assess the long-term impact on teaching practice.</ns5:p>