## 4 Experiments and Results
### The Forum of Nora
Annotated content was also enriched with images and other HTML5 media, with the intent of creating rich points of interest. For instance, to improve the understanding of the archaeological area from both a topographical and chronological perspective, basic annotations were created in the center of the forum with the reconstructive plan of the context. A similar annotation was placed as well inside the Basilica and enriched with images in order to provide further information on the mosaic floor. Complex annotations instead, were used to highlight structures, specific scene portions or areas. Furthermore, during the tour, the _focus streaming_ feature (see Section 3.8) was also employed by the virtual guide with different radii to point or raise the attention on details and areas while describing them. All the participants had the possibility to personally experiment the use of these tools (annotation, focus, layers and lighting) during the visit. This solution enabled a consistent interaction between them and the virtual guide. At the end of the tour, a questionnaire was administered to the participants: we report the outcomes from this survey to support the evaluation of the collaborative session. Figure 21: Captures from the collaborative session using a web browser. (**A**) Participants enter the session and gather as the virtual guide (red) starts the explanation; (**B**) The guide progressively activates reconstruction layers (semi-transparent volumes) and uses focus streaming to raise attention on specific hotspots; (**C**) virtual discussion phases; (**D**) The 3D scene with all layers activated. Results  
At the end of the collaborative session within the reconstructive proposal of the forum of Nora, statistics from the questionnaire and suggestions reported by users, were collected (see Figure 22). In this section, the outcomes of this general evaluation of the service will be discussed. In particular, we focused on users locations, devices (hardware) used, collaborative features used including audio (talk) and overall feedback. _Geographical distribution_. Most of the participants (90%) connected from Italy, one from Belgium. Within the Italian territory, 5 users were located in northern Italy and 3 in the center, with the server node (DN) located in Rome. _Hardware and software_. The collaborative session was experienced from 3 different classes of devices: PC (56%), laptop (33%) and mobile smartphone (11%). Windows and Mac-OS were equally distributed as main OSes in 8 devices. With the exception of the mobile device (android smartphone), all the other devices employed Google Chrome to interact with the 3D scene. _Collaborative tools_. During the session a few collaborative tools were introduced to users: (1) dynamic lighting; (2) focus pointer streaming; (3) layer switch; (4) basic (spherical) annotation; (5) free-form annotation. At the end of the session, users were invited to rank all the tools used from the most to the least useful. Users with mobile devices did not have the possibility to annotate on the scene (by design), thus this feature was evaluated by 8 users only. Outcomes revealed that the _focus streaming_ was rated by participants as the most useful (31%), followed by free-form annotation (30%) and basic annotation tools (28%). _Audio quality_. Throughout the virtual tour, communications were mainly made through voice. Thanks to the microphone of their devices, users easily spoke to each other as they were effectively visiting the site as in real life. Despite the presence of a limited delay, the audio quality was rated as good (45%) and very good (44%). A few users however, disagreed with the use of spatialized audio as it was perceived as uncomfortable. _Usefulness_. Overall, the whole group of participants involved in the tour appreciated the collaborative session. From their personal experience most of them (66%) would use this online service for research purposes (for example, team collaboration).