Archives for: September 2007

Thursday, September 20th 2007

Permalink 09:40:25, Categories: Meeting Summaries

Meeting summary - 17 Sept 2007

[Meeting summary - 17 Sept 2007] Supports vs Claims, Booleans vs Enumerations. Today's entire teleconference was dedicated to issues 20 and 21 on the issues list. Issue 20 is about the use of simple Boolean representations, in contrast to structured representations such as sets. The usual example is the representation of support for image formats. Should one have a separate Boolean property for each format (supportsGIF, supportsJPEG, etc) or should one have a set (["GIF","JPEG",...]) that then needs to be scanned to see if your specific format is supported? Meanwhile, issue 21 deals with the meaning of these Boolean values. Does "Supports XHTML" mean that the entire XHTML specification is supported 100% by the browser? If so, then unfortunately (almost) all browsers will have a FALSE value. The alternative interpretation of the property is that this is what is *claimed* to be supported, and any deviations from the claim (where true) will have to be investigated via more refined queries to the repository. Andrea supplied some background to the WURFL experience in this area: "In WURFL we found that there were many different interpretations of tags so members tried to summarise this. XML was chosen to communicate the information because of widespread support, and we went with very simple property names, and we went with Boolean values because of ease of management." Developers demonstrated a preference to work with simple Booleans, and therefore this is an important consideration for the design of the DDR API. Rotan proposed that the same degree of simplicity could be provided via the API, while still permitting the ontology to represent unbounded properties as sets/enumerations. In effect, the API can hide the nature of the ontology for those developers who prefer to keep things simple. Similarly, in cases where the entire set of values is required, the API can provide this too. Assuming the API can provide the desired Boolean values, how should developers treat these values? In practice, if a value of TRUE indicates support for a feature, it does not necessarily mean that the support is complete (e.g. GIF but not animated GIF, XHTML tables but not nested tables). Furthermore, as Bryan noted, in cases where there are alternative supported formats, the Boolean values do not indicate which of the supported formats are preferred. This idea is already present in HTTP's "q values". It may be possible to answer a question about feature support by supplying a list ordered according to preference. As a further refinement of the idea, a Boolean value could be accompanied by metadata to indicate that more information is available. For example, support for XHTML may be indicated as TRUE, but a refined query may reveal that certain XTHML features are not (properly) supported. This was described as the "yes, but" approach. Jo pointed out that if we accept the idea of representing properties as members of enumerations, we should consider the possibility that these enumerations may be extended independently by different groups. For example, one group (the DDR Core Vocab team) may decide that "GIF" will represent support for any GIF format, whereas another group may decide that "GIF" means single-frame images while "GIFa" means multi-frame (animated) images. The conflicting semantics of "GIF" means that these cannot be resolved in the same ontology, unless something like namespacing is employed. It was generally agreed that extensibility is desirable, as is simplicity. Where individual vocabularies decide to create their own values, it should be easy to do so, subsequently easy to create mappings between values known to the vocabulary and corresponding values in the ontology, and finally this extensibility should not negatively impact other groups who employ the common ontology. The group decided that this debate was a good candidate for the agenda of the joint teleconference scheduled for next week. Attendees: Matt Womer (W3C) Martin Jones (Volantis) Andrea Trasatti (dotMobi) Jongpil Yi (Samsung) Rotan Hanrahan (MobileAware) Jose Manuel Cantera Fonseca (Telefonica) Anders Ekstrand (Drutt) Bryan Sullivan (AT&T) Rafael Casero (SATEC) Jo Rabin (dotMobi) Pontus Carlsson (Drutt) Rodrigo Garcia Acevedo (CTIC)
Rotan Hanrahan

Monday, September 17th 2007

Permalink 19:47:48, Categories: Meeting Summaries

Meeting Summary - 10 Sept 2007

[Meeting summary - 10 Sept 2007] DD/UWA meeting, Next F2F, Deadline for contributions, Resolved issues [DD/UWA] Following the recent decision to host a joint meeting on the 24th with the UWA Working Group, the DD participants considered a number of topics of mutual concern to include in the agenda. This includes clarifying responsibility for the ontology, the means by which vocabularies reference the ontology, and the means by which the ontology is populated. [F2F] The next face-to-face meeting of the DDWG will take place in November in Boston, during the week in which many other W3C groups will gather for the Technical Plenary. The DDWG will take this opportunity to share information with the other groups. The agenda for the meeting will be drafted over the coming weeks. [Deadline] The properties that have been contributed to the vocabulary are now appearing on the DDWG wiki. A deadline of approximately two weeks will be established for public comments. [Resolutions] The following resolutions were made: - ISSUE-1 (the use of naming conventions in the vocabulary) has been concluded with the agreement at the London F2F that each property will have only one normative name, and all others are merely informative. - ISSUE-2 (keeping the OMA informed of DDWG progress) is concluded because two members of DDWG are now taking the role of information conduit to the OMA. - ISSUE-7 (managing aliases in the ontology) is closed because we have agreed that a property can have only one normative name. All others are merely informative. - ISSUE-9 (identifiers for HW and SW and possibly other aspects) is closed because the group has agreed that the context key should be an opaque object whose structure is therefore unknown, and undiscoverable. Attendees: Matt Womer (W3C) Rodrigo Garcia (CTIC) Rotan Hanrahan (MobileAware) Dimitar Denev (Fraunhofer) Kevin Smith (Vodafone) Jose Manuel Cantera Fonseca (Telefonica) Anders Ekstrand (Drutt) Bryan Sullivan (AT&T) Jo Rabin (dotMobi) Andrea Trasatti (dotMobi) Jongpil Yi (Samsung) Pontus Carlsson (Drutt)
Rotan Hanrahan

Sunday, September 16th 2007

Permalink 19:10:38, Categories: News

DDWG blog activity

It has been an interesting time on the DDWG blog. As you know, this is the blog where regular updates on ongoing DDWG work. It is available to anyone who would prefer not to be signed up to the public mailing list. Of course, you can always view the various archives to see what has transpired, or visit the wiki to see some of the latest technical work. So why has it been interesting on the blog? Mainly because it has attracted some attention. Unfortunately, not the right kind of attention. The blog is generally open to comments, but to date the only substantial comments to be received have come via the tried-and-trusted public mailing list. The blog comments, almost 100% of them, are spam. The DDWG blog is monitored and moderated, so none of this spam is getting through to our readers. We may have to disable commenting in light of the rise in spam, but rest assured that the public mailing list will remain available. Meanwhile, further updates on recent meetings are on their way.
Rotan Hanrahan