It's true that both HTML+RDFa and Microdata have been published in Working Drafts at the W3C. However, Microdata has never been through a Working Group Decision to publish as a First Public Working Draft while HTML+RDFa has. Microdata was added to a Working Draft after FPWD and there has since been a Working Group decision to take Microdata out of that spec. It is reasonable to expect that soon HTML+RDFa and Microdata could be in the same stage Process-wise, but it's inaccurate to portray them as being at the same stage Process-wise right now.

Since both RDFa and Microdata support the same underlying data model, and it's likely to take some time to resolve which will be the eventual winner, perhaps we should decouple the generation of the final HTML output from the markup of semantic text in articles. Since it makes no sense to implement yet another incompatible "semantic wikitext" format for internal use, we will probably end up using something that is pretty close to one or the other, buried inside templates, to perform the actual in-wiki markup. Given this, is it worth considering which is easier for template authors to write, and which is easier to convert to the other -- RDFa to microdata or vice-versa?

Perhaps the right approach for us would be to have "some" syntax for providing this info, and then generating html5 microdata and/or rdfa into the rendered html, write the triple into a smw backend store, and provide rdf/xml/n3/whatever output via the api. there are three aspects here: specify, store, output. perhaps we should look at them separately.

There were the comparsions how many bytes the semantic data definition would take in RDFa or microdata, but it certainly takes even much less bytes to define the properties in SMW. If the SMW itself is not suitable, why not to borrow the compact [[::]] property definition syntax, at least? Then it will be possible to generate separate output in any desirable format. Why the long templates with XML tags are better? Dmitriy

What would be sample SMW markup for the image example from my first post here?

I can see two major problems with using SMW syntax for input: 1) Implementing microdata-output-as-microdata is trivial, and already implemented in core. SMW syntax would still need to be implemented in core, and this would probably be nontrivial.

2) We typically set a much higher bar for new wikisyntax than for new whitelisted HTML attributes. By our regular standards, I don't see how it would be justifiable to introduce new syntax for the sake of probably a tiny number of templates.

Maybe your syntax would be better here, but I don't really see the benefits except to those who are already using SMW.

* Dmitriy Sintsov <questpc(a)rambler.ru> [Tue, 19 Jan 2010 10:40:16 +0300]: Probably even shorter: [[Work::File:meryMolyneux-terrestrialglobe-1592-20061127.jpg]] [[Title::Emery Molyneux Terrestrial Globe]] [[Author::Bob Smith]] [[License::CC-BY-SA-3.0]] (as Happy-melon suggested). Such way the output of RDFa/microdata can be managed in the Parser. The properties belongs only to the page where they are defined and are not stored in the DB.

* Aryeh Gregor <Simetrical+wikilist(a)gmail.com> [Mon, 18 Jan 2010 17:36:23 -0500]: Something like this: [[Property_name::Property_value]] I think the "third" (actually the first) value in triple will be the page where the property is defined. Also, the output of property value can be piped very much similar to the links. [[work::http://upload.wikimedia.org/...terrestrialglobe-1592-20061127.jpg]] [[title::Emery Molyneux Terrestrial Globe]] [[author::Bob Smith]] [[license::http://creativecommons.org/licenses/by-sa/3.0/us/]] While the pages with corresponding property names (work, author etc..) in NS_PROPERTY namespace will define the semantic types of data. Someone stated that square-bracket syntax is harder to parse, favoring magic words / functions. Perhaps such definitions can be replaced by semantical magic words {{PROP|Name|Value}}, implemented for the Parser. Then, SMW itself can pick up that curly-brace syntax. The advantage is, that dumps of Wikipedia will be suitable for local SMW querying, even if there will be no SMW installed at Wikiemdia servers.

Just a minimal usable subset of syntax, without the semantic queries, "concepts" and other harder stuff. Semantic data is potentially everywhere in Wikipedia pages. MW Parser may introduce a better integrated syntax with magic words, which can be later adpated by SMW for it's extended querying abiilties. Just an idea. Dmitriy

On Mon, Jan 18, 2010 at 7:47 AM, Henri Sivonen <hsivonen(a)iki.fi> wrote: 1) Output a very few pieces of metadata that would be useful to HTML consumers, like license metadata. For these, we should use microdata or RDFa, maybe just with one or two vocabularies whitelisted, and it would be simplest to just let people type it into templates via wikitext. I'm pretty certain about this.

We can always add new input formats or switch the output format later if we have good reason, though. Especially if we keep input restricted to one or two vocabularies -- or three, which for microdata is all of them right now. :)

On Mon, Jan 18, 2010 at 6:41 PM, Happy-melon <happy-melon(a)live.com> wrote: Right. We know that web spiders are interested in picking up this metadata automatically. I'm not clear what your analogy to infoboxes is about.

Ah, I see. I don't think we want to do that. There's no end to the amount of metadata you could shove into a page in machine-readable format -- we'd be talking serious markup bloat here if you start adding things on the basis of "someone will surely find it useful". I wouldn't want to add any extra output on every page unless we had a known, concrete use for it.

It's no different, except that RDFa/microdata are relatively standard, so third parties don't have to special-case MediaWiki and can use the same code to figure out licenses on all sites. That's the only advantage.

Well, the idea is you could accept microdata as input, and transform it into a different format for output if in the future you decided you didn't like microdata. So you could add the disjointness between input and output at a later date if it's needed then.

We could use this, but I don't see a big advantage over raw microdata if a) we'll be outputting as microdata at first anyway, and b) it's only expected to be used for a very few things like licenses, presumably hidden away behind templates. If it is done, though, it should be with curly braces for sanity's sake: {{#prop:author|Bob Smith}} or whatnot.

This sort of thing might be good syntax for a separate RDF stream, but I think we can keep that simpler. Instead of having {{Infobox foo|name=Bob Smith}} contain, somewhere, {{#prop:name|{{{name}}}}}, creating the triple (page name, 'name', 'Bob Smith') for the page, why not just leave out the #prop and have *every* template parameter create a triple? So {{foo|bar=baz|quuz=quuuz}} would create the triples (page name, 'foo|bar', 'baz'), (page name, 'foo|quuz', 'quuuz') with no extra markup needed. The triples could then be transformed into a more useful form by the consumer, using a language like OWL. This is something like how dbpedia.org works right now, AFAICT.

Okay, I'll grant that for an RDF-style use-case, parser functions are a better bet than the alternatives. However, I'm not sure that's the case for inline markup, in the limited cases where we want that (e.g., image licenses). The problem here is that you'd have to associate the metadata with particular phrases. You can't say {{#prop:license|CC-BY-SA-2.0}} and output that as proper microdata/RDFa -- or rather you could, but only by creating empty content nodes someplace. I guess that would work . . . it's not good practice if you're hand-authoring, and it would take a bit more space, but it might indeed make sense from our POV.

But then there's the question of writing it. The code for raw microdata/RDFa output is already written, and is pretty trivial besides. Is anyone willing to write core code to do this metadata abstraction with a parser function, and output in appropriate formats? If not, the choice is microdata, RDFa, or nothing.

Not for search engines. They're spidering all the pages anyway, so it's easier for them to not retrieve a separate page. Besides, how would they know how to find the metadata if it's not included or pointed to on the page in some standard format?

I bet very few people would bother adding metadata without a concrete use.

"Aryeh Gregor" <Simetrical+wikilist(a)gmail.com> wrote in message news:7c2a12e21001200638y759365c8oeecd8f06f761a583@mail.gmail.com... Yes, very few people would bother. Those few people would still introduce a monstrous amount of extra markup by working deep in the template stack. Doesn't take much to add kilobytes to large articles; I've added 5kb to [[Barack Obama]] myself just by adding a span round reference brackets. Just adding author metadata to citation templates would add seconds to load times for large articles. I'm not talking about exposing it in a data stream per se, I'm suggesting that that's what our internal search would be able to achieve if the metadata was accessible to MediaWiki. True, the markup Dmitry offered is more suitable. But Ryan is absolutely right. You're only thinking about the the *current* generation of formats, and assuming (maybe legitimately, I don't know) that microdata is the best format for us to use. What happens when the next generation of format(s) come out? With a format-neutral input format, MW sites can quickly adapt to accommodate it. Plus this method of data-injection will much more work to allow MW to extract the data from the wikitext, which puts our searching for photos in Berlin issue further out of reach. You could say that we're talking about different things again; that you're talking about marking up data for external use. But there's no reason why a {{#prop:foo|bar}} magic word can't *also* output some appropriate metadata format into the wikitext. Marking up in a format-neutral syntax allows us to output metadata from wikitext *and* from MW generally, and to change *both* formats at the drop of a hat. Marking up in a particular format, whatever the format is, makes it damn near impossible (or at least hopelessly hackish) to change wikitext output from one format to another, and equally horrible for MW to collect data at all.

--HM _______________________________________________ Wikitech-l mailing list Wikitech-l(a)lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikitech-l

Aryeh, you're quoting something that I purposefully said off-list in an attempt to save this mailing list from the RDFa/Microdata tumult. It was an e-mail that I specifically sent to you, Henri, Philip and David Gerard. That e-mail, which contained a heart-felt apology (in case I had come across as too aggressive) has now been openly quoted out of context. I say this because that e-mail was specifically off-list and thus nobody on the list could discover the full context of the statements above. The off-list e-mail is attached below in order to further explain why I won't be participating in this discussion. Here are the sequence of events that lead us to this point: * Aryeh Gregor posts a call to integrate Microdata into Mediawiki[1]. * Manu Sporny, noticing a number of factual errors, responds[2] to the  initial e-mail. The focus of the arguments are around the  non-maturity of both the Microdata and HTML5+RDFa proposals. * A number of e-mails are exchanged during which Manu Sporny is warned  to not use the term FUD or other charged language by David Gerard. * Manu Sporny, concerned that the debate is damaging both of the  Microdata and RDFa initiatives, decides to apologize and discuss the  issue off-list with the respondents. * Aryeh Gregor quotes portions of the off-list discussion, out of  context, and responds[3] directly to the mailing list. * Manu Sporny responds with this e-mail. [1]http://lists.wikimedia.org/pipermail/wikitech-l/2010-January/046382.html [2]http://lists.wikimedia.org/pipermail/wikitech-l/2010-January/046386.html [3]http://lists.wikimedia.org/pipermail/wikitech-l/2010-January/046466.html I will be responding shortly to the remaining questions that have been unanswered during this discussion and then leaving the discussion entirely. I don't feel that we are having a productive discussion here and the damage that I fear is resulting is the rejection of both Microdata and RDFa. If there are any further questions related to RDFa, please ask them on the RDFa Task Force mailing list (a public mailing list) and we will do the best that we can to answer them: http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/ Below is the off-list e-mail that I sent to Aryeh, Philip, Henri and David. -------------------------------- Message-ID: <4B55010B.6090607(a)digitalbazaar.com> Date: Mon, 18 Jan 2010 19:47:07 -0500 From: Manu Sporny <msporny(a)digitalbazaar.com> User-Agent: Mozilla-Thunderbird 2.0.0.19 (X11/20090103) MIME-Version: 1.0 To: Henri Sivonen <hsivonen(a)iki.fi>fi>,  Aryeh Gregor <Simetrical+wikilist(a)gmail.com>om>,  =?ISO-8859-1?Q?Philip_J=E4genstedt?= <philip(a)foolip.org> CC: David Gerard <dgerard(a)gmail.com> Subject: [OFFLIST] Re: [Wikitech-l] RDFa and Microdata in MediaWiki References: <95E5D943-BD84-4028-8FDA-8CBC7D4CE587(a)iki.fi> <4B54E525.8020100(a)digitalbazaar.com> <fbad4e141001181524t4c0622d6i4689b32510c6f426(a)mail.gmail.com> In-Reply-To: <fbad4e141001181524t4c0622d6i4689b32510c6f426(a)mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit David Gerard wrote: Hey Aryeh, Henri, Philip, Looks like I've had my hand slapped twice during this discussions. I thought this was the first warning, but David seems to think differently. That means that either I've been too aggressive or David is not familiar with the level of intensity surrounding the Microdata/RDFa debates. Both of these are negative outcomes in my mind. In the first case, know that I am not, nor ever intend to personally attack any of you. I strongly disagree with the idea of getting Microdata integrated with Wikipedia at this stage, before REC, but it is the idea that I am attacking, not any of you. If any of you took any of my statements personally, specifically Aryeh or Henri, I whole-heartedly apologize. I know each of you are doing what you feel is best for the future of the Web, just as I am. In the second case, if David feels the need to reel the discussion in, that probably means that others in the community are not reacting well to the discussion either. This is bad for both Microdata and RDFa as it sours those that are involved to using either solution. I think I've made the points that I wanted to make and then some, so, I'm going to back off on replying to most of the discussion. I'll chime in when somebody asks a direct question of me, but will eventually exit the discussion entirely. Please do your best to fact check what you guys are saying and be careful of how you phrase assertions about the past and future RDFa work - things are never as clear cut as they may seem. I hope this e-mail finds all of you in good health, -- manu PS: Tell Lachy that I hope his arm feels better soon. :) -- Manu Sporny (skype: msporny, twitter: manusporny) President/CEO - Digital Bazaar, Inc. blog: Monarch - Next Generation REST Web Services http://blog.digitalbazaar.com/2009/12/14/monarch/ _______________________________________________ Wikitech-l mailing list Wikitech-l(a)lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikitech-l

Rather than argue the same FUD for Microdata, which anybody could, I This is FUD. You are asserting your opinion without making any sort of