ACTION-30: Technology Comparison Summary

Here is the draft summary of our technology comparisons. It can also be found as Technology Comparison Summary (https://github.com/w3c/personalization-semantics/wiki/Technology-Comparison-Summary <https://github.com/w3c/personalization-semantics/wiki/Technology-Comparison-Summary> within our wiki. Providing this was my ACTION-30 from the January 6, 2020 meeting. We discussed providing this overview as an appendix in our requirements document. 

-becky


Technology Comparison Summary

The task force reviewed various vocabulary options before deciding upon the use of the data- HTML attribute syntax.  The list of technologies included:
RDFa Lite <https://www.w3.org/TR/rdfa-lite/> - (https://www.w3.org/TR/rdfa-lite/)  
HTML Microdata (https://www.w3.org/TR/microdata/)
Additional ARIA-* attributes
AUI-* a new, personalization specific set of attributes
A new single attribute, purpose, to encode both properties and values
A new single attribute with properties and values encoded using inline css syntax of key/value pairs.
An extension of the above single attribute using CSS key/value pairs and simple text content
Three new attributes for token, value, and URI, respectively
Value pairs - a personalization type attribute and an associated value attribute. 
Negotiate new personalization attributes into native host languages
Embed personalization data via JavaScript Object Notation (JSON)
Use of the existing data- attribute mechanism of HTML
We researched and discussed the positive and negative merits of the above technologies using the following criteria:
Authoring - ease of authoring and potential ambiguity between personalization and existing features
User Agents - ease of determining and parsing the properties & values and the ability to implement as an extension
Host Languages - requirement for special host language support, works in multiple languages, integrates with ARIA and HTML, easy extension of the vocabulary, and needed number of new features
Functionality - necessity of multiple properties and interaction between properties, integration with other vocabularies, likely search engine support for content alternatives, and typed value support
Strategy - avoid segregation of accessibility from other features, provide a clear path to join with other W3C personalization efforts, and stable enough to avoid modification of authored content over time

The details of our research and discussion is documented on the Comparison of ways to use vocabulary in content (https://github.com/w3c/personalization-semantics/wiki/Comparison-of-ways-to-use-vocabulary-in-content <https://github.com/w3c/personalization-semantics/wiki/Comparison-of-ways-to-use-vocabulary-in-content>)  and Prototypes with data dash * (Take 2) (https://github.com/w3c/personalization-semantics/wiki/Prototypes-with-data-dash-*-(Take-2) <https://github.com/w3c/personalization-semantics/wiki/Prototypes-with-data-dash-*-(Take-2)>)  pages in our Wiki. We presented some of these options at the TPAC 2018 Personalization Plenary Day presentation and provided a working example using the data- attribute to add personalization features.  The data- solution was recommended by representatives of several working groups attending our presentation and discussions. See the Vocabulary Implementations section in the Expainer document (https://w3c.github.io/personalization-semantics/#vocabulary-implementations <https://w3c.github.io/personalization-semantics/#vocabulary-implementations>) for further details on the use of data- attributes.