How it works
Ask each student about their own part
Turn on Group assignment when you create the assignment. That single toggle changes what every student is asked.
When students submit, each one names their team and writes one line about what they personally did. That takes a few seconds, and it does two things: it forms the team without you maintaining a roster, and it is a commitment made before the interview.
Then Viva interviews each student separately. Because they declared a part, the question is not a vague "tell me about your project" — it is "you said your part was the regression model. Walk me through how you did it." A student who built it explains it easily. A student who did not cannot, and no amount of reading the final document fixes that in the moment.
What you get back, per student
The part they claimed, in their own words · how well they defended it when probed · whether what they demonstrated matched what they claimed · the transcript quotes behind that read
Then one page shows the whole team side by side, with the teams that need attention sorted to the top. The free rider does not need to be accused by anyone. They are simply the row that could not explain the work they claimed.