Path: Multimodal & physical AI
Mark when an event starts and ends
Place event start and end times you can actually see, and mark the edge where the boundary is genuinely unclear.
- Starting level
- Comfortable with the basics
- Time
- 22 minutes
- Public lesson guide
- EN + हिंदी
You will learn to
Mark event boundaries on visible evidence and record the uncertain edge instead of smoothing it.
Why this matters
A boundary guessed to keep the timeline tidy teaches a model that a hidden action definitely happened.
Three things to remember
- Set the boundary at the first visible proof of the event.
- Mark the uncertain edge instead of extending the label over it.
- Write the frame or moment that proves each boundary.
See one example
'Pumping water' in a clip where the arm is hidden behind a pillar for three seconds.
Try the judgement yourself
Both answers respond to the task above. One of them does the job better. Which, and why?
Make something yourself
Describe a short everyday action on video — pouring tea, locking a shutter. Write where its start and end are visible, and where the boundary would be genuinely unclear.
Read further
The source is optional. The complete teaching and practice are available inside AI2Bharat.
Read the primary or official source: Ego4D video benchmark