What the Judges Actually Ask

Students prepare for the wrong interview. They memorize their poster, rehearse the abstract, and brace for a quiz on facts. Then a judge sits down, glances at the title, and asks something that sounds almost casual — "so why did you do it this way?" — and the rehearsed answers are suddenly useless. Having read projects from the other side of the table, I can tell you the casual question is never casual. It is the only question. Everything else is small talk.

A judge has minutes, not hours, and dozens of projects to separate. They are not auditing your arithmetic. They are testing one thing: do you understand your own project well enough to defend the choices inside it? Every real question is a version of that. "Why this control and not another?" "What would change your conclusion?" "What did you expect, and were you surprised?" These are not traps. They are invitations to show that the work is yours all the way down — that you could have done it differently and chose not to, for reasons.

The judge is not checking whether you are right. The judge is checking whether you would know if you were wrong.

The three questions under every question

Strip the phrasing away and almost everything a judge asks reduces to three. Why this question? — can you place your work in a landscape and say what was missing. Why this method? — can you justify a design decision against the alternative you rejected. How do you know? — can you connect a specific number to a specific claim, and name its uncertainty without flinching. A student who can move fluently among those three sounds like an author. A student who can only recite sounds like a tour guide in their own museum.

The most powerful sentence you can say

It is not a clever rebuttal. It is "I don't know — here is how I would find out." Judges are disarmed by it because almost no one says it, and because it is exactly what a working scientist says ten times a day. Certainty about everything reads as fragility; a student who has mapped the edges of their own knowledge has clearly stood at those edges. So we rehearse the unknowns as deliberately as the results. We list, out loud, the three questions most likely to land, and for each we practice the honest version of the answer — including the one that ends in a plan rather than a fact. The poster is the easy part. The defense is the project finally speaking for itself.