KML, originally designed as an external format for Keyhole's geographic data, has become, by evolution and design, a leading interchange format in the emerging "geoweb" as the WWW-embedded global repository of geographic information has come to be known. Supporting this direction, the OGC is working to bring KML into its standardization process.
KML, having been repurposed, does not arrive already perfected for its role as a geoweb underpinning, and the members of the geoweb community have not yet evolved the range of practices needed for smooth functioning of the new ecosystem.
Here is an important example. When KML content from Platial started showing up in Google Maps search results recently (under "user-created content"), we noticed a lack of attribution. Places added by our users ended up on Google pages without any information about where the content came from. Of course, this needed fixing: attribution is essential in any domain relying on user-contributed content. That is, people won't contribute without it for long. KML, unlike RSS (and GeoRSS), does not come with built in tags that point back to information sources, so KML emitters, such as ourselves, don't immediately think to include this attribution information.
Last week we had a visit from a few Googlers (John Hanke and Chikai Ohazama from Keyhole/Earth and Brandon Badger from the maps API team), and the attribution issue was one of the topics we talked about. The most direct fix is for emitters to include attribution links "by hand" in the content they emit - in particular, in the description and Snippet tags of the Placemarks. But it is also worth considering extensions to the KML standard for support of attribution. We have implemented the former fix in our own KML emitter (example), and have general ideas about how KML should be extended.
Here are some suggestions:
- Platial, and other KML emitters can and should:
- Give linked attribution to the author right at the top of the description and snippet, including the author's avatar;
- Include a link in the description back to the original post;
- Include a link in the description back to the context in which the post was found;
- KML needs recontextualization into its new role in the geoweb, where connecting content of diverse forms and sources is as important as representation of geography:
- Add tags (analagous to the link tags in the RSS channel and item elements) that link out from the geographic content within KML to other content on the web. Attribution is one application, but there are others. Such tags should be supported at root and folder as well as atomic feature levels. For example, a KML feed for a newspaper's dining column will need to point back in some manner to the source of the information, and this is an attribute of the whole feed, not just individual reviews (encoded as Placemarks).
- In the meantime, the Metadata can be used as a stopgap. For example, here is a possible (dead simple) structure for attribution metadata:
<Metadata> <authorLink> ... </authorLink> <sourceLink>...</sourceLink> </Metadata>
Metadata can be attached to folders as well as atomic features.
In closing, authors deserve proper attribution. This is a call out to Google, the OGC and everyone who uses KML to build a healthy ecosystem for the contributors to the geoweb.
--Chris Goad, chris [at] platial.com