Mobile Evaluation Log ===================== Evaluator: Nathan Age Range : 50-59 Gender: male Profession: Professor Research Fields: Visualization Years of Experience: 25 Device: HP Elitebook 840 G10 OS and Version: Debian 13 Screen Size: 27" Screen Resolution: 3840 x 2160 Web Browser: Chromium 141.0.7390.107 Ad Blocker: none Internet Connection: none Screen Recording Software: OBS Studio 32.0.1 Recording Resolution: 1920 x 1080 Date of Evaluation: 2025-09-30 Negative Findings (Problems) ----------------- o NA-Neg01 Title: Draggable Indicator in Chart Description: A Dimension in the Chart can only be moved when it is dragged by its label. This can be hard to remember. Video Clip: na-neg01-draggable.mp4 Heuristic: A06 Recognition Rather Than Recall How Reproducible?: Scroll down to any Chart → Click and Hold the label of a Dimension → Move left/right o NA-Neg02 Title: Arrow Menu hard to find Description: When seeing a chart, there is always a Menu-Button with two arrows on the top left side. Such a menu is not a standard in such applications and can be hard to find. Video Clip: na-neg02-menu.mp4 Heuristic: A02 Speak the Users' Language How Reproducible?: Scroll to any Chart → click on the button with two arrows on the left-hand side o NA-Neg03 Title: Outlier Explanation Description: In the application, there is no clear definition of an outlier. It only showcases what an outlier is. Video Clip: na-neg03-outlier.mp4 Heuristic: A04 Consistency o NA-Neg04 Title: Scatter plot Images Description: Scatter plot Images are shown for theoretical explanation. There are no Interactions on the scatter plot, making it possible to see the connections in the Chart. Most of the other discussed features have an interaction and a theoretical part. Video Clip: na-neg04-scatter-plot.mp4 Heuristic: A04 Consistency o NA-Neg05 Title: Unfinished Explanation of line selection Description: The text does not explain to the user how to select multiple lines. The text fails to tell key functionality. Video Clip: na-neg05-selection.mp4 Heuristic: A10 Help and Documentation o NA-Neg06 Title: Hiding unselected Records Description: It is possible to select multiple lines in the Chart. To make the Analysis of the Data easier, it would help to remove the unnecessary data datapoints. Video Clip: na-neg06-hiding.mp4 Heuristic: A07 Flexibility and Efficiency of User o NA-Neg07 Title: Data Table hidden Description: To analyze the data in detail, the table containing the Chart data can be very helpful. The table is however, hidden in the two arrow menu on the top left-hand side of a Chart. It is not intuitive to find it in there. Video Clip: na-neg07-table.mp4 Heuristic: A07 Flexibility and Efficiency of User How Reproducible?: Scroll to any Chart → click on the button with two arrows on the left-hand side o NA-Neg08 Title: Interaction with clusters Description: The application provides interactive operations for most of the explained topics. Such an operation is missing for clusters. Video Clips: na-neg08-clusters.mp4, na-neg08-algorithm.mp4 Heuristic: A04 Consistency How Reproducible?: Scroll down to Usage o NA-Neg09 Title: Add selected Data to table Description: The functionality to select lines in the Chart is given. For precise Data reading, it would help to add only selected Data to a Table. Video Clip: na-neg09-advanced-table.mp4 Heuristic: A07 Flexibility and Efficiency of Use o NA-Neg10 Title: Current position in Application Description: There is no overview of the whole application; the user does not know where they currently are and what he is going to do with this application. The only way to know where the user is in the application is the scroll bar. A standard for modern (web)applications is the display of the current position in some way. Video Clip: na-neg10-position.mp4 Heuristic: A10 Help and Documentation o NA-Neg11 Title: Guiding the User Description: In modern teaching applications, the user is specifically taken through and helped by the application. In this application, the user can freely choose what he does next. Video Clip: na-neg11-guiding.mp4 Heuristic: A02 Speak the Users' Language o NA-Neg12 Title: Transition Unexpected Description: The transitions between the Charts can be distracting and confusing. Most web applications use a smoother effect to not distract the user. Video Clip: na-neg12-transition.mp4 Heuristic: A02 Speak the Users' Language How Reproducible?: Scroll down until a jump between Charts occurs Positive Findings ----------------- o NA-Pos01 Title: Table is inviting to interact Description: The table on the right-hand side of the Personal Finance Dataset invites the user to interact. It is clearly displayed that the data can be displayed in the Chart. Video Clip: na-pos01-table.mp4 How Reproducible?: Scroll down to the first table o NA-Pos02 Title: Page Layout Description: The page layout is a combination of information and examples. The data is updated as the user goes through the application. Video Clip: na-pos02-layout.mp4 o NA-Pos03 Title: Individual learning Description: The application allows for individual learning. If something is not understood, the user can always go back. Video Clip: na-pos03-learning.mp4 o NA-Pos04 Title: Reversibility Description: The reversibility of the application is given. All actions are reversible for the user. Video Clip: na-pos04-reversibility.mp4 o NA-Pos05 Title: Minimalist design Description: Minimalist design is achieved. Aiding that is a good font setting. Video Clip: na-pos05-minimalist.mp4