Optimizing Virtual Annotations in 360° Mobile Museum Exhibitions: The Impact of Position and Border Design on User Experience and Visual Search Performance

Virtual reality (VR) has accelerated museum digitalization, with 360° exhibitions becoming vital during the COVID-19 pandemic. However, research on annotation design in VR remains limited. This study investigates how annotation position (top, bottom, left, right) and border design (with/without) affect user performance and experience in 360° VR museums, integrating the TAM and TTF frameworks. Using a 4x2 between-subjects design with 80 participants and semi-structured interviews with 20, we analyzed visual search performance and subjective evaluations. Results reveal significant main and interaction effects. Key findings: (1) Top and bottom positions yield superior visual efficiency; (2) Bordered designs generally enhance clarity but depend on context; (3) Bordered designs excel at bottom/right positions for acceptability; (4) Borderless annotations at the left minimize gesture interference on mobile devices. These findings provide empirical guidance for optimizing VR annotation design.