TheLearnDen Research Lab
Free Learning Resource Survival Index — Wave 2
What the second 511-URL pass confirmed after transient network failures distorted the first survival figures.
Made by TheLearnDen Research Lab · Checked 24 August 2026 · Updated
- URLs rechecked
- 511
- School confirmed-live
- 99.2%
- Hub replacements live
- 100%
TheLearnDen Research Lab rechecked the same 511 deduplicated URLs on 24 August 2026. This second pass ran about 63 hours after Wave 1, outside the originally proposed 24–48-hour window; that timing deviation is recorded rather than hidden. No sampling was used.
Headline findings
- Dead-resource resurrection: 0 of 172 URLs returned as a working page in Wave 2 — 0.0%.
- School carrying pages: 252 of 254 pages with a confirmed outcome were live — 99.2% confirmed-live. Of all 257 probes, 252 were live (98.1% observed-live), 2 were confirmed hard failures (0.8% of confirmed outcomes) and 3 connection resets remained inconclusive (1.2% of probes).
- Suggested replacements: 9 of 9 exact replacements and 10 of 10 hub replacements were live — 100.0% in both classes.
The previous 93% school figure and 80% hub figure treated transient network failures as dead. They are superseded by this Wave 2 result and the explicit live/dead/inconclusive convention above.
Outcome table
| Cohort | Probed | Live | Confirmed dead | Inconclusive | Reported rate |
|---|---|---|---|---|---|
| Previously dead resource URLs | 172 | 0 resurrected | 172 still non-working | 0 | 0.0% resurrected |
| School carrying pages | 257 | 252 | 2 | 3 | 99.2% confirmed-live |
| Exact replacements | 9 | 9 | 0 | 0 | 100.0% live |
| Hub replacements | 10 | 10 | 0 | 0 | 100.0% live |
Method
Wave 2 used the same 511-URL set as Wave 1: 172 distinct dead-resource URLs, 320 carrying-page URLs and 19 suggested replacement URLs. Node's global fetch used a browser-like user agent, a 12-second timeout per hop and up to five manual redirect hops. Response bodies were capped at 64KB and classified from HTTP status, redirect destination, title and body evidence. Challenge pages were not counted as proof that a resource was live.
Rates follow a three-outcome convention:
- Live:
live-equivalentorredirect-useful. - Confirmed dead: a hard HTTP failure.
- Inconclusive: timeout, connection reset, TLS or other network result that does not prove death.
The confirmed-live rate excludes inconclusive probes from its denominator. The observed-live share retains every probe in its denominator and is shown separately.
Limitations
- Wave 2 ran about 63 hours after Wave 1, not within the originally proposed 24–48-hour interval.
- Classification is automated and based on capped response evidence; outreach or replacement changes still require page-level human review.
- Three school pages remained inconclusive after connection resets. They are not silently counted as dead or live.
- Access and redirect behaviour can change after the recorded probe window.
Files
recheck-wave2-2026-08-24.jsonl— complete per-URL records and evidence.recheck-wave2-2026-08-24.csv— the same 511 records in tabular form.summary-wave2-2026-08-24.json— machine-readable counts behind every figure on this page.