While virtual reality (VR) has great educational potential, current implementations predominantly emphasize audiovisual simulations, neglecting olfactory and haptic stimuli and thereby compromising the physical fidelity of VR learning environments. Meanwhile, conflicting findings on the impact of immersion level on learning outcomes, coupled with limited research exploring the interaction between physical fidelity and immersion level, have impeded the widespread adoption of VR in education. Therefore, this study aimed to examine the effects of physical fidelity (multisensory stimuli vs. no multisensory stimuli) and immersion level (immersive VR vs. desktop VR) on learning experiences (cognitive load, learning motivation, and quality of experience) and outcomes (procedural, factual, and conceptual knowledge) in VR-based fire-safety education. A two-by-two factorial experiment was conducted with 120 Chinese university students. The results showed that multisensory stimuli significantly reduced the intrinsic cognitive load of learners. Immersive VR surpassed desktop VR for bolstering learning motivation, particularly in terms of attention, relevance, and satisfaction. Physical fidelity and immersion level have significant interaction effects on long-term retention of conceptual knowledge and satisfaction. Incorporating multisensory stimuli into immersive VR enhances the quality of experience. Our findings have significant implications and value for the application of multisensory stimuli and VR technology in education.

Immersive virtual reality (IVR) has demonstrated significant potential in educational contexts. Nonetheless, prior IVR implementations have primarily focused on visual and auditory simulations, neglecting olfaction, which has limited immersive learning. To address this gap, we conducted an experimental study involving 64 students to examine the impact of integrating olfactory stimulus into IVR systems for fire safety training. Participants were randomly assigned to the control group (without olfactory stimulus, n = 32) or the experimental group (with olfactory stimulus, n = 32). The results indicated that the integration of olfactory stimulus significantly promoted high-arousal positive emotions, increased sense of presence, and reduced cognitive load—although it did not significantly improve learning performance. Thematic analysis further revealed that the incorporation of olfactory stimulus provided learners with an immersive learning experience. Moreover, this IVR system with olfactory stimulus had a high quality of experience. These findings have significant implications for the practice of learning in IVR and multisensory learning theory.