Mobile Evaluation Log ===================== Evaluator: Michael Age Range : 40-49 Gender: male Profession: Senior Researcher Research Fields: Chart, AI 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: 2025-09-24 Negative Findings (Problems) ----------------- o MI-Neg01 Title: Buttons have no descriptions Description: The buttons of the table at the start have no description or context menu for further explaining their usage. Video Clip: mi-neg01-table-buttons.mp4 Heuristic: A02 Speak the Users' Language How Reproducible?: Scroll until the table on the right-hand side is displayed o MI-Neg02 Title: Adding data from table to chart Description: The user has no indication why he cannot add the data he filled into the table to the Chart. Video Clip: mi-neg02-add-data.mp4 Heuristic: A05 Error Prevention Only When: not all fields in the table are filled out How Reproducible?: Scroll until the table on the right-hand side is displayed → Click on the "+" in the top right corner of the table → add a heading and two rows of data to the new column o MI-Neg03 Title: Tooltip useless Description: The tooltip in the chart shows the name of the label when hovering over the label. Video Clip: mi-neg03-useless-tooltip.mp4 Heuristic: A08 Aesthetic and Minimal Design How Reproducible?: Scroll the first Chart is displayed → hover over the name of a dimension o MI-Neg04 Title: Tooltip Invert Description: There is no tooltip displayed for the inverting of a dimension, and the icon is not intuitive for the user. Tooltips are often used in modern applications. Video Clip: mi-neg04-tooltip-invert.mp4 Heuristic: A06 Recognition Rather Than Recall How Reproducible?: Scroll the first chart is displayed → hover over an arrow beneath a dimension's label o MI-Neg05 Title: Tooltip Filter Description: There is no tooltip displayed for the filters of a dimension, and the icon is not intuitive for the user Tooltips are often used in modern applications. Video Clip: mi-neg05-tooltip-filter.mp4 Heuristic: A06 Recognition Rather Than Recall How Reproducible?: Scroll the fist Chart is displayed → hover over a filter border in the Chart o MI-Neg06 Title: Data Values Description: When hovering/selecting a line in the chart, the user expects to see the values. Video Clip: mi-neg06-line-values.mp4 Heuristic: A06 Recognition Rather Than Recall How Reproducible?: Scroll to any Chart → hover over/select a line o MI-Neg07 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: mi-neg07-multiple-lines.mp4 Heuristic: A10 Help and Documentation o MI-Neg08 Title: Inconsistent explanation Description: Dataset explanation is done differently in the Personal Finance Dataset and Heart Health Dataset. Video Clip: mi-neg08-explanation-inconsistent.mp4 Heuristic: A04 Consistency How Reproducible?: Scroll to "Personal Finance Dataset" → read explanation → Scroll to "Heart Health Dataset" → read explanation o MI-Neg09 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: mi-neg09-transition.mp4 Heuristic: A02 Speak the Users' Language How Reproducible?: Scroll down until a jump between Charts occurs o MI-Neg10 Title: Refresh not explained Description: There is no clear explanation for what refresh can be used for in this web application. Video Clip: mi-neg10-refresh.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 MI-Neg11 Title: Table of contents and current position 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: mi-neg11-position.mp4 Heuristic: A10 Help and Documentation o MI-Neg12 Title: Dataset Purpose Description: The user is not told what the purpose of the different datasets is. Video Clip: mi-neg12-dataset-purpose.mp4 Heuristic: A10 Help and Documentation o MI-Neg13 Title: Cluster Interaction Description: The application provides interactive operations for most of the explained topics. Such an operation is missing for clusters. Video Clip: mi-neg13-cluster-interaction.mp4 Heuristic: A04 Consistency How Reproducible?: Scroll down to "Usage" o MI-Neg14 Title: Interactive correlation Description: Correlations are not shown interactively like outliers. There is an interactive button for outliers, but not for correlations. Video Clip: mi-neg14-interactive-correlation.mp4 Heuristic: A04 Consistency How Reproducible?: Scroll down to "Usage" → Looking for Correlations Between Dimensions o MI-Neg15 Title: Case Study Clicking Description: The blue highlight in the Case Study can be misinterpreted as clickable, because this design is often used in mobile applications. Video Clip: mi-neg15-case-study-clicking.mp4 Heuristic: A02 Speak the users' language How Reproducible?: Scroll down to "Case Study" o MI-Neg16 Title: Case Study Explanation Description: The case study has no explanation beforehand; the user needs to figure out for themselves what they need to do. Video Clip: mi-neg16-case-study-explanation.mp4 Heuristic: A10 Help and Documentation How Reproducible?: Scroll down to "Case Study" o MI-Neg17 Title: Interactive Operations Split Description: The interactive operations are split into two separate groups. The verbal explanation is at the start of the application, and the interactive Case study is at the end. Video Clip: mi-neg17-operations-split.mp4 How Reproducible?: Scroll down to "Case Study" o MI-Neg18 Title: Interact Directly Description: The application wants to explain to the user how the system works before giving full control. With the Interact Directly button, this does not hold up anymore. Video Clip: mi-neg18-interact-directly.mp4 Heuristic: A04 Consistency How Reproducible?: Scroll down to "Case Study" o MI-Neg19 Title: Test the User Description: A lot of similar learning applications test the knowledge of the user after teaching them. PCEE only has free interaction and does not follow this. Video Clip: mi-neg19-test-user.mp4 Heuristic: A04 Consistency o MI-Neg20 Title: Coordinated Multiple Views Description: The screenshot in the section "Coordinated Multiple Views" does not fit in with the rest of the application. Video Clip: mi-neg20-coordinated-multiple-views.mp4 Heuristic: A04 Consistency How Reproducible?: Scroll Down to Coordinated Multiple Views o MI-Neg21 Title: Reset Selection Description: If the "Interact Directly" Button is pressed and the user moves to another part of the application and back, it is set to the initial state. Video Clip: mi-neg21-reset-selection.mp4 Heuristic: A01 Feedback How Reproducible?: Scroll Down to Case Study → Click "Interact Directly" → scroll back to the top of the page → Scroll Down to "Case Study" Positive Findings ----------------- o MI-Pos01 Title: Moving Dimensions Description: Moving dimensions is a key feature for the visualization of Parallel Coordinates. It is a necessary tool to find correlations and compare the different dimensions of the data. Moving dimensions in any Chart works without a problem. The Dimensions can be moved in any order. Video Clip: mi-pos01-moving-dimensions.mp4 How Reproducible?: Scroll down to any Chart → Click and Hold the name of Dimension → Drag it to the left or right o MI-Pos02 Title: Show Outlier Description: Showcasing the finding of an outlier is a great interactive learning tool. Video Clip: mi-pos02-outlier.mp4 How Reproducible?: Scroll down to "Usage" → Click on the "Show Outlier" Button → Look at the Chart on the left → Click on "Show Outlier" Button o MI-Pos03 Title: Case Study Description: The Case Study lets the user go through different actions on Parallel Coordinates. It is an interactive explanation of possible steps that can be taken to analyze the data. Furthermore, it is a great tool for teaching as the user can get to see the steps as they are taken. Video Clip: mi-pos03-case-study.mp4 How Reproducible?: Scroll down to "Case Study" Bug Findings ----------------- o MI-Bug01 Title: Multiple Entry Description: When adding more than one new column, the user edits all at once. Video Clip: mi-bug01-double-entry.mp4 How Reproducible?: Scroll Down to the Table → add 2 columns → enter value in any field o MI-Bug02 Title: Filtering not working Description: In the first Chart, filtering on "Income" does not filter the uppermost polyline. Video Clip: mi-bug02-filtering.mp4 How Reproducible?: In the first Chart, try filtering on "Income" o MI-Bug03 Title: Overlapping icons Description: Sometimes the range slider in a Chart overlaps with the Invert Arrow beneath the label. Video Clip: mi-bug03-overlap.mp4 How Reproducible?: No clear indication o MI-Bug04 Title: Chart broken by Case Study Description: The Chart can be broken if the user steps through the case study too fast. Video Clip: mi-bug04-chart-broken.mp4 How Reproducible?: Could not be reproduced