Fix the score domain
Synthetic eligible exposure units have integer scores 0–99. Local map assigns A to 0–39, B to 40–79 and holdout to 80–99, all inclusive. Each score gets exactly one bucket; this is a deterministic teaching allocation, not a claim of randomisation or representativeness.
| Unit/score | Bucket | Reason |
|---|---|---|
| U1/39 | A | Last A score |
| U2/40 | B | First B score |
| U3/79 | B | Last B score |
| U4/80 | Holdout | First holdout |
Apply the bucket intervals
- Validate integer 0–99 score
- Apply inclusive interval membership
- Check exactly one assignment
- Record holdout without creative exposure
An out-of-domain or missing score stays unassigned; it cannot be placed in holdout by default.
How many possible scores belong to A, B and holdout?
Show the worked answer
40,40,20 respectively, totaling 100 unique scores. Score 40 belongs only to B.
Test boundary records
| Case | Decision or result | Reason |
|---|---|---|
| Use A0–40 and B40–79 | Reject overlap | Score 40 would have two buckets |
| Use supplied partition | Complete unique allocation | Every 0–99 score once |
Keep allocation revision with the score source and unit identity. The bucket map prepares records; it does not deliver impressions or demonstrate a valid statistical experiment.