The Key 4 AIProve
A verifier, running in your browser.
A grader that decides what is correct has to exist before a model can be trained against it. Once it exists, it can grade anyone's model. This page is that idea made visitable.
Sample harness. The answers below are hand-written illustrations, not model outputs. The grader is genuinely executing on this page; view source. When the real harness and logged answers exist, they replace this, and this label changes.
Answer set A-
Answer set B-
Answer set C-
Lenient also accepts dd/mm/yyyy dates and ignores currency symbols on amounts.
1. Payment: paid 4,250.00 to Meridian Tools on 3 March for invoice 88-A.
Answer set A
- Amount
- 4250.00
- Payee
- Meridian Tools
- Date
- 2026-03-03
- Reference
- 88-A
Answer set B
- Amount
- 4250.00
- Payee
- Meridian Tools
- Date
- 03/03/2026
- Reference
- 88-A
Answer set C
- Amount
- 4250.00
- Payee
- Meridian Tools
- Date
- 2026-03-03
- Reference
- 88-A
2. Payment: invoice 12-B settled with Solantis Freight for 980.50 on 14 April.
Answer set A
- Amount
- 980.50
- Payee
- Solantis Freight
- Date
- 2026-04-14
- Reference
- 12-B
Answer set B
- Amount
- 980.50
- Payee
- Solantis Freight
- Date
- 2026-04-14
- Reference
- 12-B
Answer set C
- Amount
- 985.00
- Payee
- Solantis Freight
- Date
- 2026-04-14
- Reference
- 12-B
3. Maintenance log: on 2 May, Pump P-204 was down 15.00 hours after a seal failure, work order WO-2291.
Answer set A
- Hours down
- 1.50
- Equipment
- Pump P-204
- Date
- 2026-05-02
- Work order
- WO-2291
Answer set B
- Hours down
- 15.00
- Equipment
- Pump P-204
- Date
- 2026-05-02
- Work order
- WO-2291
Answer set C
- Hours down
- 15.00
- Equipment
- Pump P-204
- Date
- 2026-05-02
- Work order
- WO-2291
4. Maintenance log: conveyor belt C-12 needed 3.25 hours of repair on 21 June for a motor fault, work order WO-2317.
Answer set A
- Hours down
- 3.25
- Equipment
- Conveyor belt C-12
- Date
- 2026-06-21
- Work order
- WO-2317
Answer set B
- Hours down
- 3.25
- Equipment
- Conveyor belt C-12.
- Date
- 2026-06-21
- Work order
- WO-2317
Answer set C
- Hours down
- 3.25
- Equipment
- Conveyor belt C-12
- Date
- 2026-06-21
- Work order
- WO-2317
5. Shipment: consignment of 620.00 kg moved by Ashgrove Freight on 8 July, reference 77-E.
Answer set A
- Weight, kg
- 620.00
- Carrier
- Ashgrove Freight
- Date
- 2026-07-08
- Reference
- 77-E
Answer set B
- Weight, kg
- 620.00
- Carrier
- Ashgrove Freight
- Date
- 2026-07-08
- Reference
- 77-E
Answer set C
- Weight, kg
- 620.00
- Carrier
- Ashgrove Freight,
- Date
- 2026-07-08
- Reference
- 77-E
6. Shipment: 2,499.99 kg carried by Pallister Marine Freight on 30 July, reference 41-F.
Answer set A
- Weight, kg
- $2499.99
- Carrier
- Pallister Marine Freight
- Date
- 2026-07-30
- Reference
- 41-F
Answer set B
- Weight, kg
- 2499.99
- Carrier
- Pallister Marine Freight
- Date
- 2026-07-30
- Reference
- 41-F
Answer set C
- Weight, kg
- 2499.99
- Carrier
- Pallister Marine Freight
- Date
- 2026-07-30
- Reference
- 41-F
7. Lab result: glycated haemoglobin measured at 8.75 percent on 11 August, order number LAB-63-G.
Answer set A
- Result
- 8.75
- Analyte
- Glycated haemoglobin
- Date
- 2026-08-11
- Order number
- LAB-63-G
Answer set B
- Result
- 8.75
- Analyte
- Glycated haemoglobin
- Date
- 2026-08-11
- Order number
Answer set C
- Result
- 8.75
- Analyte
- Glycated haemoglobin
- Date
- 2026-08-11
- Order number
- LAB-63-G
8. Lab result: fasting glucose result of 140.50 on 2 September, order number LAB-22-H.
Answer set A
- Result
- 140.50
- Analyte
- Fasting glucose
- Date
- 2026-09-02
- Order number
- LAB-22-H
Answer set B
- Result
- 140.50
- Analyte
- Fasting glucose
- Date
- 2026-09-02
- Order number
- LAB-22-H
Answer set C
- Result
- 140.50
- Analyte
- Fasting glucose
- Date
- 02/09/2026
- Order number
- LAB-22-H
9. Meter reading: meter EM-05-I read 340.00 kWh on 9 September, reference MR-05-I.
Answer set A
- Reading
- 340.00
- Meter ID
- EM-05-I
- Date
- 2026-09-09
- Reference
Answer set B
- Reading
- 340.00
- Meter ID
- EM-05-I
- Date
- 2026-09-09
- Reference
- MR-05-I
Answer set C
- Reading
- 340.00
- Meter ID
- EM-05-I
- Date
- 2026-09-09
- Reference
- MR-05-I
10. Meter reading: meter WM-99-J read 12,600.00 litres on 15 September, reference MR-99-J.
Answer set A
- Reading
- 12600.00
- Meter ID
- WM-99-J
- Date
- 2026-09-15
- Reference
- MR-99-J
Answer set B
- Reading
- 12600.00
- Meter ID
- WM-99-J
- Date
- 2026-09-15
- Reference
- MR-99-J
Answer set C
- Reading
- $12600.00
- Meter ID
- WM-99-J
- Date
- 2026-09-15
- Reference
- MR-99-J
Method
How a grade is decided.
- The task family and why it was chosen. Ten short records across payments, maintenance logs, shipments, lab results and meter readings, the kind institutions already keep and already have to check.
- The rules, stated before any answer is graded. A value must match ground truth to two decimal places; a date must be ISO format; a name is compared trimmed and case-folded; a reference must match exactly.
- What strict and lenient mean and why both exist. Strict is the rule as written. Lenient additionally accepts dd/mm/yyyy dates and ignores a currency symbol on an amount, because some acceptable answers are stricter about form than the question required.
- What the grader cannot see, and therefore cannot judge. It cannot see whether an answer was reasoned correctly, only whether the final field matches. It cannot see intent, and it cannot see a right answer expressed in a form the rule did not anticipate.
- How losses are recorded, and where. A failed grade is not hidden; it is written to the Ledger with a dated note, the same as a claim that held.
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The Ledger
Every claim we make, with its status.
- HeldEvery regulator we quote is quoted from its primary text, with its status stated.
Thirteen entries; two are drafts, one a consultation, one a proposed issue, two publisher's abstracts.
- ClaimedAI transformation and agentic AI are what we do; owned and provable is how.
Stated on the front page. Every agent we build or assure is graded by a verifier.
- ClaimedThe Key 4 Learning is the first Studio company. Its product is Clarify.
Product page published; brochure v0.1.
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