Annotator Cookbook

Annotator Cookbook

Step-by-step recipes for common workflows.

Basic Annotation Workflow

1. Log in with your credentials
2. Select a file from the dropdown — files prefixed with your username are assigned to you
3. Navigate to the region of interest:
   • Use Previous / Next buttons to step through the file by one window
   • Change Window Size (in seconds) for a wider or narrower view
   • Type a specific time in Anchor Time (format: Jun 01 2005 01:33 PM)
   • Drag on the minimap (range selector at the bottom) to jump to a region
4. Box-select a time range on the main plot by clicking and dragging
5. Click an activity button (Chair Stand, TUG, 3m Walk, 6min Walk) to create the annotation
6. Optionally toggle Segment, Scoring, or Review flags
7. Optionally add Notes in the text field
8. Click Export to save your work

Always click Export before closing the browser or switching files. Unsaved annotations are lost on server restart.

Adding Flags to an Existing Annotation

1. Select the annotation in the summary table below the plot
2. Click the flag button (Segment, Scoring, or Review) to toggle it
3. Flags are visual: cross hatch, dots, or spiral on the overlay
4. Click Export to save

Adding a File-Level Review Flag

You can flag an entire file without selecting a time range:

1. Use the Review multi-select widget in the sidebar under each activity type
2. These create annotation rows with no start/end time — they represent a file-level flag
3. Click Export to save

Deleting an Annotation

1. Select the annotation row in the summary table
2. Click Delete
3. Click Export to persist the deletion

Reviewing Another User's Work (Admin)

1. Open the Impersonate dropdown in the header bar (visible to admins only)
2. Select the user whose work you want to review
3. Their file assignments and annotations load in place of yours
4. You can view, edit, or add annotations on their behalf
5. Changes are saved to their annotation file
6. Select your own name to return to your own view

Managing Users (Admin)

1. Scroll to the User Admin panel at the bottom of the sidebar
2. Add a user: Enter username and password, select role (admin/annotator), click Add
3. Remove a user: Select from the list, click Remove
4. Change role: Use the role dropdown next to the user's name
5. Changes take effect immediately across all sessions — no server restart needed

Navigating Large Files Efficiently

• Start with a large window (e.g., 3600s = 1 hour) to get an overview
• Use the minimap to spot regions of activity (visible as signal amplitude changes)
• Zoom in by reducing the window size (e.g., 60s) and setting the anchor to the region of interest
• The LTTB downsampling ensures smooth rendering regardless of file size