SilVR: Comparing Diegetic and Non-Diegetic Interfaces in an Immersive VR Simulation for Silviculture Education

Background Silviculture education requires understanding complex, spatially distributed ecological processes and the long-term effects of forest management decisions. These concepts can be difficult to convey through traditional teaching methods. Virtual Reality (VR) offers an immersive, interactive way to explore complex systems in domains such as silviculture, and design considerations, such as diegesis, may influence learning outcomes. Aim This study introduces SilVR, an immersive VR simulation for teaching silviculture concepts, and investigates the effect on user engagement, usability and learning outcomes of two user interface (UI) paradigms: diegetic (lesson components and controls integrated into the virtual environment, e.g., physical buttons, maps) and non-diegetic (elements presented in a consistent, non-immersive format, e.g., transparent panels, floating text). Method SilVR was developed using a predictive forest growth model, allowing users to explore forest outcomes under different management regimes. A between-participants study was conducted as part of a graduate training workshop, with factors of diegetic and non-diegetic information presentation. Nineteen forestry students participated in the study. Each participant completed a pre- and post-intervention knowledge assessment. The system captured user behaviour, and participants completed self-report measures: Intrinsic Motivation Inventory (IMI), presence, and a general feedback questionnaire. Results Knowledge scores significantly improved following the intervention. While there was no significant interaction effect due to diegesis on knowledge, students in the diegetic condition progressed through scenes more quickly and exhibited stronger preference behaviour. Conclusion Immersive VR effectively supports learning in complex domains such as silviculture. Design considerations, such as diegesis, play a key role in learner engagement and interaction. These findings offer implications for the design of educational VR simulations for forestry and other complex system domains.