Working Group rules

1. W3C Process Document, with links to Patent Policy, CEPC, Guide, etc.
   Also includes (4.2. Content of a Charter):
   [...] The process for the group to approve the release of deliverables (including intermediate results).
2. Group Charters contain a success criteria section.

Independent Interoperable Implementation?

While no exhaustive list of requirements is provided here, when assessing that there is adequate implementation experience the Director will consider (though not be limited to):

• is each feature of the current specification implemented, and how is this demonstrated?
• are there independent interoperable implementations of the current specification?
• are there implementations created by people other than the authors of the specification?
• are implementations publicly deployed?
• is there implementation experience at all levels of the specification’s ecosystem (authoring, consuming, publishing…)?
• are there reports of difficulties or problems with implementation?

Planning and accomplishing a demonstration of (interoperable) implementations can be very time consuming. Groups are often able to work more effectively if they plan how they will demonstrate interoperable implementations early in the development process; for example, developing tests in concert with implementation efforts.

w3c/w3process issues

• #167 define "independent" , February 2018
• #522 Single implementations and interoperability: showing implementation experience with fewer implementations, August 2021

Implementation

• Does a js library count (querySelector)?
• Does a plugin/extension count (ARIA)?
• Does an e-reader count (EPUB3)?
• Should the source code be publicly available?
• Can the implementation be a beta/alpha version and not shipped/adopted?
• Does the implementation license matter?

Independent

• How much implementation code can be shared before two implementations are counting as one?
• Do implementations provided by a participant count less than one provided by outsider?
• One library used by everyone, like WOFF/brotli or URL?

Interoperable

Producer (0 or more) -> Consumer (0 or more)

• Producer: Authors, authoring tools, servers, devices, etc.
• Consumer: Renderers, Parsers, Validators, Aggregators, etc.

Interoperable Testing

• required vs optional features?
• one test per feature? one test per MUST/SHOULD/MAY?
• Should we test every single key provided by UI Keycode Events, or color provided by CSS Colors or screens for multi-screen api?
• A function with many possible enumerated return values - do we have to show each of them is returned?
• Do you need every class of agent conformances (e.g. in HTML there are authoring tools, Browser agents, non-JS browser agents, validators, ...)?
• Do we have to test SHOULD NOTs?
• If you update a REC, do you need to retest everything?

W3C Technology spread

• Data vocabularies: DCAT, DID, JSON-LD, VSSo, or manifest?
• Term definitions: XML Infoset
• Profiles: DFXP Transformation, DFXP Presentation and DFXP Full
• Protocols: SOAP, Open Screen
• Guidelines: WCAG
• Can the Generic Sensor become a REC if there is no support for any of sensor-specific APIs?
• what about the security/privacy/a11y/i18n sections, such as not sharing user behaviors?

Timing

How much does timing of external events matter? What opportunities would be missed?

Timed Text proposed charter

When considering suitability to advance any feature beyond Candidate Recommendation, at least two independent factors of verification MUST be demonstrated, which may come from any of:

• Presentation implementation
• Content
• Validating implementation

For example, a feature MAY be advanced beyond Candidate Recommendation if it has been demonstrated to be implementable on the basis of an open source implementation that successfully processes content from an independent implementation.