## 6 Conclusions and Future Work  
This study explored the effects of two different navigation aids (outdoor vs. indoor-outdoor navigation app) and spatial ability skills on university campus wayfinding performance and perceived workload. This paper also identified the challenges in indoor-outdoor campus wayfinding using mobile navigation aids. An experiment was conducted with twenty-two participants divided into control and experiment groups using Google Maps and MazeMap, respectively, to complete a time-bound university campus wayfinding task. Both quantitative and qualitative data was collected using multiple methods, including spatial ability test, questionnaires, interview, and observation/field notes. Based on the findings, the following conclusions and design implications are presented for facilitating university campus wayfinding by improving navigation systems:  
* Seamless indoor-outdoor navigation is crucial for university campus wayfinding, and navigation apps must provide support for indoor navigation. * The spatial ability skills of participants affect their perceived workload and wayfinding performance. Moreover, the mental workload experienced by the wayfinders also impacts their wayfinding performance in university campus navigation. Therefore, it is important to consider cognitive load and spatial knowledge acquisition when designing campus navigation systems. * The employed navigation aids do not affect the workload and wayfinding performance, but they can impact the cognitive load and wayfinding strategy of participants in university campus wayfinding. Therefore, navigation aid can play a role in reducing cognitive load and shaping human spatial ability to improve wayfinding and navigation. * The app usage experience, usability and technical issues in the navigation app can affect the cognitive load of users. Thus, the design of indoor-outdoor campus navigation applications should focus on reducing the cognitive load of wayfinders by improving usability and technical issues in the app and catering to users with different prior experiences (novice and experienced). The effective use of multimodal technology integrating multiple modalities can enhance the usability and user experience of navigation systems and facilitate learning the application. * The campus navigation apps should help wayfinders in spatial knowledge acquisition. The wayfinders with higher spatial ability skills experience less workload and are more confident navigating indoor-outdoor campus wayfinding. Modern digital technology, such as 3D models, AR maps and appropriate visualization, can assist individuals in acquiring spatial knowledge. * Landmarks can decrease the cognitive load on the wayfinders and assist them in spatial knowledge acquisition. Therefore, the integration of appropriate landmarks is important in designing university campus navigation systems. * Some other design recommendations for indoor-outdoor campus navigation applications include additional route and location information, real-time location, improved location search, improved location visualization, notifications and alerts, assistance or help, consistency, easy to understand and updated location changes. Some of the directions for future work include focusing on conducting experiments on a larger scale to compare the differences between navigation aids with different user groups and on multiple campuses, exploring the impact of different wayfinding strategies on the workload and wayfinding performance with navigational aids, and exploring the impact of gender and age difference on wayfinding performance. Future studies could also investigate topics such as how user's spatial knowledge can be improved through navigation aids, how to adapt navigation aids for different types of wayfinders and their strategies and investigate the effectiveness of multimodal instructions on wayfinding performance in navigation tasks with different cognitive loads.