Will That Be Adaptation Or Alternation?
You say Adaptation, I say Alternation.
Luca Passani, the creator of WURFL (The Wireless Universal Resource FiLe) and of Global Authoring Practices for the Mobile Web, contacted me on some of the topics discussed here. He takes issue with some of the thinking involved in the One Web approach of the W3C Mobile Initiative. The Introduction to the GAP outlines some of his thinking.
Without speaking for either side, it struck me that some of the debate might be clarified by introducing a new word. Certain things we’re all agreeing on. We all would like a ubiquitous web where people can access content with a satisfactory user experience whatever the device they’re using. We’re all agreed that this involves different content appropriate to the device and that this can be done either server-side or client-side. Adaptation has been used as the umbrella word to describe that process.
In practice as different entities and companies involved in the Mobile web are setting up their websites, two very different approaches are involved. Some go with the W3C approach that a single URI should give access to appropriate content for all devices. Others are using different URIs for different devices. In other words, they suggest alternative URIs dependent on the device being used. The closest English word to that notion would seem to be the word, Alternation. The thinking is described in greater detail in the article below.
If you have a better word for such a process than Alternation, then let’s hear it. Otherwise why not go with Alternation.
Related: Adaptation Or Alternation
Tags: Mobile, alternation
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BPWrap
April 9th, 2007 at 8:29 pm
I think the “debate” here is mostly in his imagination. Fortunately. I encourage anyone to read these two links:
http://www.w3.org/TR/2006/WD-mobile-bp-20060412/#OneWeb
http://www.w3.org/TR/2006/WD-mobile-bp-20060412/#tc
I don’t think anyone disagrees that “one web” is a lovely idea. All content available in an appropriate format on all devices? nice! The disagreement may come in how far to take this idea and how to implement it. MWI suggests a very limited application of this idea for mobile.
Some disagree about how to author “one web”-friendly content for mobile. Can you write one XHTML page and use CSS media selectors to get a mobile and desktop site from it? do you need to use an adaptation engine? should you just write two versions of your site? I think the answers are no, no, yes personally. Luca agrees. The MWI actually has nothing to say about this question directly, but, implicitly promotes authoring entirely separate content for mobile devices since it asks sites to be ready to deliver content to very limited devices — like ones that can’t even support tables. A natural (and perhaps most natural) approach to doing this is just authoring a separate mobile site.
Some disagree about how to implement “alternation” as you call it (I’d call it “content negotiation”) Adaptation? server-side redirects? browser redirect from a canonical URL? I personally think the latter is a good way to go. This W3C TAG finding agrees:
http://www.w3.org/2001/tag/doc/alternatives-discovery.html . This is a nice “hybrid” approach in my mind. Again MWI has nothing to say on this one actually. The MWI output is really about the mobile stuff you deliver, irrespective of how you decided that you needed to deliver that mobile content.
I’m glad that the MWI recommendations aren’t overreaching and suggesting particular implementation strategies, and also glad that there still does not appear to be a real difference of opinion here.
April 10th, 2007 at 3:40 pm
Thanks for stopping by, Sean, and for providing the links, which are most informative. In the post I was deliberately neutral. However I would respectfully take issue with your statement:
I don’t think anyone disagrees that “one web” is a lovely idea. All content available in an appropriate format on all devices? nice!
I for one disagree since I don’t believe ‘one web’ is as all encompassing as that. It’s called ‘one web’, I believe, because it deals precisely with a single URI from which all devices should be able to derive ‘thematic consistency’. It certainly sounds nice, just as perfection sounds nice. However it doesn’t provide a practical road for much development activity.
Given the wide variety of devices, I do not believe a greater proliferation of CSS style-sheets and encouragement for all to use them will make ‘one web’ happen. A more practical approach that many even outside the standards-compliant supporters are now following is to have different URIs for different devices. I have dubbed that the ‘multi-web’ approach.
I see too many people assuming that ‘one web’ is now the only preferred way. They often get frustrated as they run into the technical challenges that ‘one web’ represents. I was also seeing Adaptation suggested as the only process needed for both ‘one web’ and ‘multi-web’ solutions. I think it’s much clearer if we have different words to apply to the two situations. Adaptation for ‘one web’: alternation for ‘multi-web’. If you know where you want to end up, you can then choose the right route.
April 11th, 2007 at 4:09 am
Developers, no need to worry. One-web has no meaning. The W3C gang has repeatedly failed to define it what it means in practice.
Do like me: ignore one-web, build usable mobile services and live happily thereafter.
Luca
April 11th, 2007 at 7:52 am
Hi Barry,
The W3C is developing DIAL (Device Independent Authoring Language) in an attempt to overcome some of the challenges inherent in creating Web content for multiple scenarios. One goal is that a single Web page can be authored and then the appropriate markup selected for delivery, using a declarative approach.
The ‘alternation’ (or ’selection’) use cases in DIAL are embedded as conditions within the markup and resolved by a DIAL processor(s). The intention is that the final markup delivered to a browser realises the authors intention when delivering to that kind of device or access condition (PC, mobile, 3G, location, etc.)
DIAL is a working draft and any comments would be much appreciated: http://www.w3.org/TR/dial-primer/
Cheers,
Kevin
April 11th, 2007 at 8:28 am
Hi Kevin. Your contribution is most welcome: thank you for that. The DIAL approach seems interesting. However it seems to be driven by an unspoken goal that a single URI should ‘work’ and provide a route to ‘thematic consistency’. This scores high on the ‘purity’ (of concept) scale but I wonder how well it scores on the ‘practicality’ scale. On the ‘practicality’ scale, the only worthwhile measure is how well the body of stakeholders (companies, developers, etc.) takes up the approach and uses it in real-world applications.
I’ve only rapidly skimmed the DIAL Primer and it clearly deserves more serious treatment than could occur in a comments section of a blog post. However I noted the following:
The definition of Multiple Authoring reads as follows:
In summary, it is stated that DIAL is arguably more efficient and convenient, whereas for Multiple Authoring (in other words Alternation) the associated development and maintenance costs are usually considered prohibitive. I wonder how events will unfold over the next few years and which approach will turn out to be the world’s choice.
Regards.
Barry
April 11th, 2007 at 5:37 pm
About DIAL, WALL, http://wurfl.sourceforge.net/java/tutorial.php has done for years what DIAL can only achieve in theory (where do I download DIAL?).
WALL lets you write an application that renders in XHTML, CHTML and even WML depending on device capabilities. Simple, Fast and Cheap…pick THREE!!!
Luca
April 11th, 2007 at 6:31 pm
Thank you, Luca, for that reference. Perhaps I could add to your Simple, Fast and Cheap criteria, the objective that every device should also not merely receive a viewable content but rather receive a content that delivers a satisfactory user experience. I do not believe that can always be achieved by taking a single content package and then treating it to make it acceptable to the target devices.
I am not sure that I like that Multiple Authoring concept, but at least it conveys the sense that different devices may require a design process specific to that device in order to deliver a satisfactory user experience. That I think is what is implied by such efforts as the Design Guide specifically for dotMobi websites (PDF).
April 12th, 2007 at 3:51 am
Brian Fling did a good job with that document (BTW, you may want to fix the link above. It’s broken). One of the shortcomings is that it is based on W3C MWIBP. Admittedly, the dotMobi guys are smart enough to give more importance to reasonable practices and less (much less) the BP practices that happen to be wrong or useless, so the Design Guide is overall very good.
For the record, one of the BP practices I dislike the most is the one which forbids the usage of tables. Tables are a devlopers best chance to place a picture and text/links side by side. CSS cannot deliver this, while tables can deliver this effect pretty consistently across devices.
Luca
April 12th, 2007 at 4:37 am
Thanks, Luca. Link is fixed.
April 12th, 2007 at 8:34 am
Whilst DIAL could (in theory) meet some of the use cases provided by WALL, the goals of these technologies are not the same.
DIAL aims to allow the author to declare under which delivery contexts a given block of content/markup is rendered. Delivery context covers more than static device capabilities and wireless devices: the decision to include content can be based on user state (pre-pay or post-pay, age, preferences), device state (current battery life, screen orientation, ambient light, current connection speed) as well. Both fixed and wireless devices are in scope.
The expressions of interest so far in DIAL have included intranets (single authoring for PC and mobile use) and mobile portals (where age suitability checks, current 3G or GPRS connection speed and roaming state etc. unfortunately add complexity beyond device capability). As Luca says, it’s theory so far, and we are working on evolving the specification and test implementation.
Cheers,
Kevin
April 12th, 2007 at 9:44 am
That certainly will make DIAL most impressive, Kevin. The only concern I might have is that Feature Creep may mean you will never get there. Sometimes it’s better to run with what can be made to work fairly quickly.
April 12th, 2007 at 10:01 am
Nothing worse than feature creep
In DIAL you make the features yourself (i.e., the expressions which are evaluated to determine if content is delivered or not). So it’s as creepy as the implementor wants it to be, or it can be nice and light too.
April 13th, 2007 at 6:34 am
[...] Barry Welford presents Will That Be Adaptation Or Alternation? posted at StayGoLinks, saying, “Making your website viewable in mobile devices such as cellphones is a mighty challenge if you try to follow the W3C’s ‘One Web’ Adaptation process. Better and simpler is to design specific cellphone web pages: that’s called Alternation.” [...]
April 13th, 2007 at 2:11 pm
[...] Related: Will That Be Adaptation Or Alternation? [...]
April 14th, 2007 at 8:19 pm
Does it matter how we do it as long as we’re not punishing the user with a poor interface because they’re on a mobile.
My understanding of thematic consistency is to show different formats of content on the same urls or to redirect through to the version suited for mobile. Nice in principle, not always workable in practice, sometimes separate sites are the best option.
WALL is an awesome tool, I’ve used for some time on a couple of sites and as far as ready.mobi testing goes one scores 4.86 which is a lot higher than average though it fails 4 tests at the w3 mobile validator.
Where’s the adaptation on this site, alternation or whatever you want to call it? My user agent is a Nokia N7’s and I see the same as FireFox.
Is it just me or is that just a little ironic?
WordPress Mobile Plugin
April 15th, 2007 at 6:17 pm
You’re right, Andy, re adaptation on this site: there’s certainly no alternation here. However I do say this is written from a desktop perspective. I’m sure I could do much better if I created a mobile version.