Assessment after the assistant: a working defence of the viva
Written assignments are a leaky vessel. Oral defence, portfolio review, and process-based assessment recover what AI displaces — and they were better all along.
The interesting thing about the assessment crisis is that it was already a crisis. The arrival of generative AI did not break a working system; it stripped a layer of paint off a system whose underlying problems were already known and tolerated.
What the written assignment was for
The written essay, set as homework, has been the workhorse of secondary-school assessment for a century. It does several things at once: it asks the student to read, to take a position, to organise that position, and to defend it in prose. The grade rewards the artefact, but the learning — the part the teacher cares about — happens in the doing.
The trouble is that the artefact and the doing are now separable. They were always separable in principle (a parent could write the essay; a student could plagiarise from a friend). What the assistant changes is the cost of separation: from significant to negligible.
The viva is not a workaround
What I want to argue is that the oral defence — the viva voce — is not a defensive retreat from the assistant. It is a more direct probe into the learning the essay was always trying to elicit.
In a viva, you cannot outsource your interior. The examiner asks: "you wrote this. What did you mean by X?" If the student wrote the words but does not own them, the gap is visible immediately.
What it costs
Twenty-eight students, ten minutes each, twice a term: that is roughly five teacher-hours a fortnight. The cost is real. The case I want to make is that the cost is comparable to the cost of marking twenty-eight essays well, and that the evidence yield is much higher.
What it gives back
The thing I did not expect, when I first ran a viva-based assessment cycle, was the change in student preparation. Knowing that you will be asked, in person, what you meant — knowing that the artefact alone will not stand — changes how students read, draft, and revise. The viva is not just an assessment; it is a teaching instrument.
The protocol I now use is documented in a separate post. This piece is the argument; that piece is the recipe.