Video Segmentation Guide
A practical guide to choosing and timing video segments for annotation.
General Rule
Each segment should mainly represent one clear behavior or activity.
If the behavior changes significantly, create a new segment.
Cheating Segments
For cheating behavior, include enough time to show the full behavior:
before the behavior → actual cheating behavior → behavior ends
Example:
- 45s: Candidate starts looking away from the screen
- 50s: Candidate begins reading from a phone
- 63s: Candidate puts the phone away and continues answering
Recommended segment:
45s – 64s
Do not mark the entire video as cheating if the cheating only happens during a small part of it.
If different cheating behaviors happen at different times, create separate segments.
Example:
40s – 58s — Using a phone
72s – 91s — Reading from another screen
110s – 125s — Receiving help from another person
Clean Segments
You do not need to annotate every normal part of the video.
Focus on normal behaviors that could look suspicious, such as:
- Looking away while thinking
- Looking around different parts of the screen
- Other normal interview behavior that may look unusual
Example:
125s – 143s
The candidate looks down several times while thinking before answering, but is not using another device or receiving outside help.
Long periods of completely normal behavior usually do not need a separate Clean segment.
Segment Length
There is no strict required length.
Use enough time to clearly understand the behavior.
Typical examples:
- Short clear action: 5–15 seconds
- Normal behavior: 10–30 seconds
- Reading or using an external resource: 20–60 seconds
- Continuous cheating behavior: can be longer than 60 seconds
Do not make a segment longer or shorter just to match a fixed duration.
Choosing the Start and End Time
A segment should contain enough context to understand what is happening.
Avoid segments that are too short.
For example:
53s – 56s
may only show the candidate looking down, without enough context to understand why.
A better segment might be:
48s – 61s
This can show the candidate answering normally, looking down for a period of time, and then returning attention to the interview.
Key Rules
Cheating: Capture the complete cheating behavior with enough surrounding context.
Clean: Focus on normal behaviors that could easily be mistaken for suspicious behavior.
Split the segment when the main behavior changes.