## 3 Results
### Online Platform
#### 3.3.2 Case Study 8: \"The CHISel Platform\"  
The Cultural Heritage Information System (CHISel) is a multi-user 3D annotation system developed at the University of Granada, Spain [109; 110]. It enables cultural heritage researchers to manage the spatial relationships of artifacts and restoration data. CHISel handles non-geo-referenced information, organizing it in layered sets referencing points on the artifact's surface. Users can edit, render, query, compose, and analyze the 3D replicas of artifacts. The system features include organizing and communicating various data types on the model, and adding and editing visible layers, colors, and text to facilitate teamwork and research [111] (see Figure 11).  
User Interactions  
CHISel users can create and annotate extended information layers on 3D models of archaeological artifacts, linking data to any part of the model's surface. The model can be enlarged or rotated for improved inspection and analysis. Sections can be color-coded and labeled for collaboration and future reference. The software supports the storage and sharing of extensive data, crucial for preserving restoration processes. Multi-user collaboration is facilitated by ensuring consistency and accuracy across all functions, requiring standardization for effective data tracking and manipulation.  
Evaluation Method and Results  
The evaluation aimed to perform a usability study of the CHISel interface of the first working prototype. The focus was on accuracy, user-friendliness, effectiveness, and efficiency, rather than user attitudes. The software, still in development, was assessed by trained HCI evaluators due to its complexity. Key usability factors included a low learning curve, domain-specific usability, system feature complexity, and multi-user collaboration. A cognitive walkthrough was chosen to evaluate learnability and system functionality. Four representative users tested the system, providing detailed observational and verbal data on user perspectives.  
Conclusions of Case Study 8  
Several usability issues of varying intensities were identified for tasks such as model preparation and layer creation (Table 7). Design improvements were identified from feedback during cognitive walkthroughs. The method provided insightful data on task effectiveness with the application interface. Lessons were learned on preparing for evaluations, running the CW with real participants, and handling the rich information provided. The full description and results can be found in the student's HCI master's project report and the usability findings are published in a relevant journal [112].  
\begin{table}
\begin{tabular}{c c l l} \hline
**CW Task** & & **Issues Found** & **Usability Issue Type** \\ \hline \multirow{7}{*}{1. Model Preparation} & - & User must use keyboard arrows to adjust resolution & - & Font/visual crowding \\  & - & Unnecessary bold text & - & Consistency \\  & - & No difference between ”chg” and ”achg” file types for saving & - & Consistency \\  & - & Saving to a folder creates extra step & - & Navigation \\  & - & Frequent saving errors & - & Efficiency \\  & - & Unnecessary ”ok” button & - & Feedback \\  & - & \"Loading triangles” message holds no meaning & & \\ \hline \multirow{7}{*}{2. Creation of Layers} & - & Many clicks required on ”name box” & - & Minimal click rule \\  & - & Uncertainty of saved values & - & Feedback \\  & - & ”Size box” name ambiguous & - & Labeling/meaning \\  & - & ”Ok” should be changed to “save” & - & Feedback/error prevention \\  & - & Pop-up window disruptive to view of model & - & Pop-up \\  & - & Presence of pen tip is assumed for coloring mode and not & - & Feedback/for correct use \\  & & rotation of model & - & Efficiency/training \\ \hline \end{tabular}
\end{table}
Table 7: Compilation of usability issues and issue types found, organized by topic.  
Figure 11: Showing the geometry and roughness of an artifact in CHISel.