How it works
Two minutes of speaking. Nothing extra for the teacher.
Viva sits between the homework a student hands in and the mark a teacher gives it. It does one thing: establish whether the student can explain their own work, and hand the teacher the evidence either way.
- 01
The student submits homework
A photo of their exercise book on WhatsApp, or a submission inside your LMS — exactly what they do today. Viva reads the work, including handwriting, and works out what was actually answered.
On WhatsApp a student joins once with a class code. In an LMS, the viva is attached to the assignment your teacher already set.
- 02
Viva picks what to ask about
It asks about questions the student got right — chosen at random from the substantive ones, never the trivial recall items.
Defending a correct answer under unpredictable selection is the sharper signal. A student who can’t explain what they got right didn’t do it. And because nobody can predict which question is picked, the only way to be ready is to understand all of it.
- 03
They answer out loud
The question arrives as a voice note. A 60-second think window, then the student records when they are ready. Follow-up questions probe wherever the answer is thin.
Voice only — a spoken answer cannot be pasted from anywhere. The whole thing is one sitting of about two minutes, with exactly one replay.
- 04
The teacher receives the evidence
Homework, recording, transcript and an understanding signal, delivered to WhatsApp or written into your gradebook.
No marking, no dashboard to learn, no second login. The teacher accepts it, overrides the score, or asks for a re-viva.
What the teacher receives
Everything they need to judge it. Nothing to mark.
The homework, the recording, the transcript, and an assessment of how well the student explained it — on the work they were going to look at anyway. Then a decision only they can make.
Adaeze U.
SS2 · Chemistry · Today, 08:40
Written work was correct, but under the viva she could not explain the mole concept and appeared to recite a copied definition. Long pause before answering, and the answers read like written prose rather than speech.
for review, not a grade
How it was assessed
- Conceptual understanding28 · 50%
Could not say why the ratio is 2:1.
- Reasoning under follow-up30 · 30%
Deflected the follow-up; repeated the definition.
- Ownership of the work45 · 20%
Gap between a clean written answer and the spoken defence.
Worth a look
- Read-aloud cadence — Answers sounded read, not spoken
- Response latency — Two-minute pause before the first answer
Observations, not accusations. Viva never concludes that a student cheated.
The conversation
- Viva0:00
Your homework says the ratio of hydrogen to oxygen is 2 to 1. Why is that, in your own words?
- Adaeze U.2:20
The mole is the amount of substance containing as many particles as there are atoms in twelve grams of carbon twelve.
her voice - Vivafollow-up2:50
That is the definition of a mole — but why is the ratio here 2 to 1 specifically?
- Adaeze U.4:10
Em… it is because of the balancing. The teacher said so.
her voice
The homework she submitted
Q3. Balance: H₂ + O₂ → H₂O. Student: 2H₂ + O₂ → 2H₂O. The ratio of hydrogen to oxygen is 2:1.
The original photo is attached for the teacher to open.
The guardrails
A child misjudged once is a school lost forever.
So the product is built to be low-stakes and human-judged. These aren’t settings — they are how it works.
A think window, not an ambush
Sixty seconds of deliberate silence before recording opens — time to plan, sketch, and settle nerves. The student chooses when to start.
No trick questions
Every question is about work the student already did. Viva never introduces new material and never tests something that wasn’t in the homework.
The teacher decides. Always.
The score is labelled an understanding signal, for review. Viva has no authority to grade a child and none to accuse one. Nothing reaches a gradebook as a verdict.
The audio always goes with the transcript
Speech recognition is genuinely weak on Nigerian-accented English, and we won’t pretend otherwise. That is exactly why the teacher hears the student rather than reading a machine’s version of them.
Consent first, and retention you control
Parental consent is collected before a child records anything. How long recordings are then kept is agreed with your school and written into the data-processing agreement — short by default, longer if you have a reason.
A flag is an observation, not a verdict
“Answers sounded read rather than spoken” is something for a teacher to weigh. It is never a conclusion, and a student is never told they were flagged.
Viva+
And 48 hours later, it teaches.
Today a student defends their work and gets nothing back. Viva+ closes that loop: two days after the viva, they receive a short revision — the question they defended, their own answer, and the fuller explanation.
The teacher approves it first, in the same screen where they saw the verdict, so it costs them nothing extra. If they haven’t approved it, it waits.
The 48-hour gap is deliberate. Returning to a problem after a delay forces a second attempt at recall, which is when learning actually consolidates.