Can I control the difficulty of the interview?

1

2

1. 1Understanding — can they explain and defend the reasoning?
2. 2The two numbers must add up to 10.

There is no difficulty slider, because a number on a slider means nothing across a first-year seminar and a graduate methods course. The controls are more specific than that.

• Duration. A 3-minute Mini stays on the surface; 10 or 15 minutes reaches the second and third follow-up, which is where depth actually lives.
• Weights. Understanding-heavy interviews ask "why" and "what if"; authenticity-heavy ones ask "walk me through how you got here".
• Custom questions. The most direct lever: write the hardest question you would ask in a viva and it gets asked.
• Instructions. Viva calibrates to the task you describe. "Undergraduate intro lab" and "capstone research" produce visibly different conversations.
• Grade level. K-12 classes (including IB and AP) get shorter, plainer questions about concrete choices; undergraduate work is expected to defend its claims; graduate work gets methodology and literature questions. The scrutiny is the same at every level — only the register changes.