Community-Reviewed Credibility Signals

W3C Internal-Draft Community Group Report,

Sandro Hawke
GitHub w3c/credweb
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Credibility signals are observations, made by humans or machines, which are used in deciding how much to trust some information. This document specifies some types of these observations which seem particularly useful in online credibility assessments, especially when assisted by machine processing and a network of people and systems making related observations. It also includes some guidance on how data expressing these observations (credibility data) can be exchanged online. The choice of which signals to include, and what to say about them, was made by the W3C Credible Web Community Group and is expected to be revised periodically.

Status of This Document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at

This version of this document has not been approved or endorsed by anyone.

GitHub Issues are preferred for discussion of this specification.

Publication as a does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

This document was produced by a group operating under the W3C Patent Policy. The group does not expect this document to become a W3C Recommendation. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.

This document is governed by the 1 March 2019 W3C Process Document.

§ 1. Introduction

TBD. See intro to 2018 version

§ 2. Signals

§ 2.1. Date Website First Archived

DefinitionThere was a website operational at URL [ ] as early as isodate [ ], as shown in the archive page at URL [ ]
  • Website Existed As Of Date
  • Website Age
  • First Known Website Archive
  • Website Release Date
  • Signal
  • FairlyEasyToVerify
  • Interoperable
More specific thanDate Website Created
Similar toDomain registration date

§ 2.1.1. Examples

Under construction.

§ 2.1.2. Motivation

whyHardToGamenew attackers will have to acquire an existing website with a site identity suited to their attack, and there aren't likely to be that many such sites, driving the price up. Older attackers have had a longer time to be discovered and unmasked. It will, however, still be feasible to game this signal, especially in the years after this signal becomes adopted, since there will be a more clear market for establishing "sleeper" sites.
  • sites that have been around a long time have probably had more of a chance to develop good internal quality controls.
  • sites that have been around a long time, if they are problematic, are more likely to have been flagged as such, all other things being equal.
  • sites that have been around a long time have generated enough content/information upon which an assessment of quality can be rendered.
  • newer sites will have an even harder time reaching an audience
  • reduced innovation on the web, as ranking on this signal presents an additional barrier-to-entry

§ 2.1.3. Availability

methodForObtainingbrowsing through, starting with the URL of the site, looking for the earliest snapshot that still looks like it was still generally the same site.
issueWithAvailabilityIt is limited by the practices of available and trustworthy archiving services. If none of them archived your site, you're out of luck. If one of them is compromised, that will devalue use of this signal from that archive.

§ 2.2. Corrections Policy

DefinitionThe news website with its main page at URL [ ] provides a corrections policy at URL [ ] and evidence of the policy being implemented is visible at URL [ ]
  • Corrections Policy Claimed
  • Corrections Policy Present
  • Signal
  • FairlyEasyToVerify
  • Interoperable
More specific thanTBD
Similar toNo Warranties Policy

§ 2.2.1. Examples

Under construction.

§ 2.2.2. Motivation

whyHardToGamethe signal has three parts, a policy, evidence of updates or a feed, and taken together with a public engagement contact (separate signal) it makes easier for humans to verify
  • news media sites that publicly assert a Corrections Policy and publish a feed of corrections are indicating willingness to be open to scrutiny both around mistakes in publishing, and whether they are actually implementing.
  • sites that show a record of corrections over a period of time indicate commitment to principles of accuracy and practice.
  • many sites may assert a policy when asked, it may not be public, and they may not have a feed, but they may be following an ad-hoc practice
  • many sites providing information around public affairs (NGOs, associations..) consider Internet pages as soft and simple update/overwrite them to correct an error, without disclosure. The signal is more relevant to News sites
  • a bias towards larger, professional news organizations that have the resources to maintain three expressions of a corrections practice
  • a bias against organizations that have not provided online visibility to some of their practices

§ 2.2.3. Availability

methodForObtainingbrowsing through, starting with the URL of the site, looking for the earliest snapshot that still looks like it was still generally the same site.
  • a site can often mention its corrections policy non-obviously on one paragraph on its general ethics/journalism policies page, or a public engagement page. I.e. there may not be a standalone URL for this particular policy at all.
  • a site may or may not have a "feed page" that lists all recent corrections in one page; but evidence of corrections may be found in individual stories where corrections were made. This may require searching effort.