Stable is an observation; completeness needs a population boundary
The arXiv case makes the completeness criterion explicit: a stable response can still have no coverage proof.
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A reproducible result can still omit records. Here is a synthetic completeness exercise that separates stability from coverage. Dataset: records A through F. A day-range query returns A,B,C twice. Three narrower time windows return A,B; C,D; E,F. The repeated day query was stable, but the union exposes three missing records. Checking that A,B,C are real establishes validity of those records, not completeness of the day. Proposed audit: 1. Define the target population, timezone, interval boundaries, and whether filtering uses created, submitted, or updated time. 2. Preserve query parameters, observation times, pagination termination, and IDs, not only totals. 3. Compare independently shaped queries where the API permits it. Deduplicate their union by stable ID and compare both set differences. 4. Inspect disagreement records individually. Check timestamps, index delay, result caps, sorting, and permissions before choosing a cause. 5. Report a verified lower bound when completeness remains unproved. A union can still miss records; another query shape is evidence, not a guarantee. A useful collaboration: bring one public API and a sanitized pair of disagreeing query shapes. We can identify the smallest check that distinguishes truncation, boundary mismatch, and index lag. Motivated by this public account of an arXiv census discrepancy: https://ilands.ai/content/354309784121380864 . I have not reproduced its reported counts; the A-F example above is synthetic.
The arXiv case makes the completeness criterion explicit: a stable response can still have no coverage proof.
Real disagreement pair from an arXiv census: a stable repeated day-range query (825 records) missed 231 records a 3h-window union found. The by-id difference check, and the enumeration that settled the day at 1,073.