Editorial policy

The source tiers

Every factual claim on this site is traced to a source, and every source is graded. The grade appears next to the source in the list at the foot of each article, so you can see what a claim rests on without leaving the page.

• Tier 1. A search engine's own documentation, a published standard such as an RFC, a patent, or a peer-reviewed paper. Anything stated as fact about how an engine behaves should have a Tier 1 source behind it.
• Tier 2. A reputable industry publication, a conference talk by an engineer who works on the system, or original research with a published method. Used for context and for things engines do not document.
• Tier 3. General reference material. Used sparingly, and never as the only support for a claim about how search works.

A claim we cannot source at Tier 1 or Tier 2 is either written as an observation with the method stated, or left out. It is not written as a fact.

How an article is researched

1. The question the article answers is written down first, in the words a reader would use.
2. Primary documentation is read before any secondary commentary, so the commentary is checked against the source rather than the reverse.
3. Where a claim is testable on a site we control, it is tested before it is written, following how we test.
4. The draft is written answer-first: the direct answer, then the mechanism, then the caveats.
5. Sources are attached to specific claims, not gathered into a reading list at the end.

Review

Articles are reviewed by a second person before publication where one is available, and the reviewer is named in the article's byline area when so. Review checks three things: that every factual claim has a source, that the source actually says what the article says it says, and that nothing has been stated with more confidence than the evidence supports.

Dates and updates

Each article shows a published date and, where they differ, a modified date. The modified date changes only when the substance changes: a correction, a new section, a claim revised because the underlying behaviour changed. It does not change for a typo fix, a formatting change, or to make the article look fresher. Refreshing dates without changing content is a practice this site treats as dishonest.

Corrections

When something is wrong, the page is corrected rather than quietly deleted, and the correction is noted on the page. If the error was significant enough to have misled someone acting on it, the note says what the page previously said.

Send corrections through the contact page. A correction with a primary source attached will usually be live within a day.

Independence

No company, tool or agency pays to appear on this site, and no mention is sponsored. If the site's funding model changes, the change will be disclosed on the about page and labelled on the pages it affects, before it takes effect.

Use of AI

Language models are used for drafting assistance and editing, in the same way a spell checker or an outline is. They are not used to generate factual claims, and nothing is published that a named person has not verified against the sources listed on the page. Any article where that is not true would not meet this policy and should be reported as an error.