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UserInteractionLog

Specs
Name UserInteractionLog
Classification attribute
Parent <Page>
Required no
Syntax UserInteractionLog="option"
Options N (default) interaction logs are not created
Y interaction logs are created for each page
Dependencies SlicerOpenCV required Slicer Extension as described in Getting Started (used to capture CPU Uptime)

Description

The main function of the User Interaction Log feature is to capture the XY screen coordinates of the four corners of every viewing window, along with the IJK values corresponding to the loaded image volumes displayed within those windows. As the user interacts with the images by scrolling through them, this coordinate information is continuously recaptured and added to the log file.

A user interaction log may be used in conjuction with eye tracking software which records XY screen coordinates of eye movements over time. By cross-referencing the XY screen coordinates recorded by the eye tracking system with the corresponding IJK values of the loaded image volume, it is possible to determine the specific area of the image that the user was focusing on at a given time point.

Due to its close association with eye tracking, enabling this feature results in a fixed viewing environment, which, in turn, restricts all movable aspects of the application. This includes actions such as minimizing or resizing the application and adjusting the size of the viewing windows. This lockdown happens on the first encounter of a Page with the attribute UserInteractionLog="Y" and will remain in effect for the remainder of the Session.

When you enable the UserInteractionLog feature for a Page element, the Image Quizzer will:

  • lock down all adjustable sizing aspects of the display (at first encounter and effective for the remainder of the Session)
  • generate a log file that records the viewing window XY screen coordinates and the IJK values of the loaded image volumes displayed within those windows.

Log details

Following is a list of the information captured in each log file:

- CPU Uptime, Time,
- Viewing window layout (TwoOverTwo, OneUpRedSlice, FourUp, SideBySideRedYellow),
- Viewing window name (Red, Green, Yellow, Slice4),
- Corner location (Top Left, Top Right, Bottom Left, Bottom Right),
- Screen coordinates X,Y for corner location
- Viewing window height, width (pixels),
- Background image name I,J,K,
- Foreground image name I,J,K,  (zeros if no foreground image)
- Background transformation 4x4 matrix (XY to IJK),
- Foreground transformation 4x4 matrix (XY to IJK)   (zeros if no foreground image)

CPU Time Rounding

Editing the UserInteractionLog.csv file in Excel may cause rounding of significant digits for CPU Uptime and coordinate values.

Example

See the user interaction log example for a script that uses this feature.

Results

User interaction logs are unique to each XML Page that has the UserInteractionLog attribute set to "Y" and are consequently stored in the user's results folder within their respective Page subfolders. When the user clicks the Next button to load a new Page of images, a new log is generated to capture the interactions specific to that Page. Conversely, if the user presses the Previous button, the captured information is added to the existing log created for the previous Page.

The following tree structure represents the output for the script provided in the example referenced above.

The log files are located in a subfolder created for each Page of the quiz XML file.

.
└─ImageQuizzer/
    └─Outputs/
        └─UsersResults/
            └─Observer1/
            └─Test_UserInteraction.xml
                ├─PgGroup1_Patient 1_CT/
                │ └─UserInteractionLog.csv
                ├─PgGroup2_Patient2_PET PSMA/
                │ └─UserInteractionLog.csv
                │...