Data Sources
Every fact on this site traces to one of the source classes below. Safety-critical values come only from Tier 1 official documentation; retailer data is used for price and availability only; everything carries a retrieval date so you can judge freshness yourself.
Last updated: 2026-08-24.
Source classes and reliability tiers
| Tier | Sources | Used for | Restrictions |
|---|---|---|---|
| Tier 1 — Official documentation | Official product manuals; manufacturer specification pages; CPSC (recalls, regulations); NHTSA (car seats); FDA (where relevant, e.g., breast pumps); official government regulations; official recall notices; recognized standards bodies where publicly available | All safety-critical fields: weight/height limits, rear-facing limits, installation and tether rules, infant-insert requirements, expiration/lifespan rules, recall status, certification claims, regulatory claims | Sole acceptable basis for safety-critical claims. Two independent Tier 1 sources preferred where available. |
| Tier 2 — Authorized retail | Listings from authorized retailers and verified marketplace pricing (e.g., Amazon Creators API) | Price, availability, current offers, bundle contents as sold | Never used for specifications or safety claims — listing specs are frequently wrong or conflated across variants. |
| Tier 3 — Context only | Public standards summaries, reputable press coverage of product launches | Background context, launch timing, line-up orientation | Never the sole basis for any published factual claim; always superseded by Tier 1 when Tier 1 exists. |
Conflict rule: fail closed
If two Tier 1 sources conflict — say, a manual states one rear-facing limit while the manufacturer's product page states another — no definitive claim is published. The comparison shows the conflict itself, for example: "Current sources conflict on this limit. Verify the current product manual before use." A plausible-looking average is never published. This applies to every safety-critical field without exception.
Retrieval-date discipline
- Every sourced value is stamped with its retrieval date. Spec tables cite it in the caption ("retrieved 2026-08-23"); source lists show per-source access dates.
- Dates are shown to readers, not hidden in metadata, so freshness can be judged before trusting a number.
- Stale values are rechecked before republishing. If a stored record is older than its category's recheck interval, the source is re-fetched first; if re-fetching fails, affected fields fall back to UNKNOWN rather than silently persisting old numbers.
- Prices are re-verified at publish time and always paired with live retailer links, because prices drift fastest.
- Recall status is checked against CPSC/NHTSA immediately before publish and on every scheduled recheck thereafter (see recall monitoring).
Sources deliberately excluded
- Anonymous blogs, forums, and social-media threads — unverifiable provenance.
- Retailer customer Q&A and reviews — useful signal for shoppers, not an acceptable basis for published specifications.
- AI-generated aggregator articles — circular sourcing with no accountable origin.
- Unlicensed reseller listings — frequently mislabeled variants or regional models.
- Anything requiring confidential access — only publicly available documentation is used.
See it applied: each comparison page ends with a numbered sources list including retrieval dates — e.g., Joolz Aer² vs Bugaboo Butterfly 2. Related: AI methodology · Editorial policy · Corrections