Immersive Virtual Reality (iVR) has reached a level of technological maturity that enables its use for the general public. However, further investigation is needed into the optimization of iVR applications and particularly, their design features in relation to various user characteristics such as age and previous iVR experience. To solve this issue, this study evaluates a Cultural Heritage dissemination experience in iVR, tested in a real-world setting, the Museum of Burgos (Spain), with participants from three age groups: children, young adults, and older adults. The iVR experience was structured in four levels of progressively complex interaction. A control group was formed to view a video containing the same dissemination content. A total of 206 participants completed a three-steps assessment measuring prior knowledge, User Experience (UX), and learning outcomes. The findings emphasized that iVR's strengths, immersion and interactivity, must be strategically optimized to outperform more well-stablished dissemination formats like video. The results showed that children responded positively to high interactivity; their motivation and rapid adaptation supported the use of interactive formats, provided cognitive demands are gradually introduced. Young adults exhibited the highest adaptability and fastest completion times, performing well across all interaction types, though with moderate UX ratings. Older adults preferred soft interaction and immersive aesthetics, achieving better learning outcomes in this context but extending the time to complete the iVR experience.
