Tuesday 29 September 2009

The Joy of (con)Text

It's a common geo-rant (thanks AGI'09) that metadata cause alternatively boredom or angst among geo-geeks - why? because we know our data, our professional audience does too, but our wider audience does not. In other words, if we don't write metadata, no-one else will understand the context later on. I found a clear example, when I mapped Captain Cook's ships logs a while ago, and posted on ArcGIS Online beta:

This dataset and the thumbnail image will show, for example, that Captain Cook's logs miss his historical landing at Botany Bay in Eastern Australia, as well as his last voyage ending with his demise in Hawaii. Dennis Wheeler, adjunct at the National Maritime Museum in Greenwich UK, revealed the following: even though the Royal Navy enforced strict guidelines to record weather and location, James Cook was notoriously lax in this; the CLIWOC team simply couldn't transliterate some of his ships logs! This is not only a very early example of data standards, but also a current illustration of why standards are important.

This blog's second-last post compared the WOEID to GUWI, as Garry Gale showed how powerful geospatial context is in location identifiers. I recently looked up the US recovery.gov website, which allows the public to scrutinise how monies earmarked for recovery programs were spent in which regions. And like everyone does on webmaps, I went straight to my old neighbourhood where my daughter was born: That detail is telling, as I criss-crossed that neighborhood with my very pregnant wife then very baby daughter (around the New Year luckily for me in Texas!), and know every dip and hillock north of the M Streets in Dallas. Lo and behold, that map has every detail in it!

In my previous life as a structural geologist, I often used stereo-photos and -readers. I always had to adjust my eyesight to restore the relief, as for some reason I first saw hills as valleys. And so I did above, until the creeks helped correct the image in my mind. This is another illustration of the importance of context. And I had a glimpse a few years ago, into how much effort went into that web service, not only to link finances to geography (metadata = required), but also base maps that allow scale-dependency, and all the data to text into those bleeping metadata tables.

“Meanwhile back home at the ranch”, oilelefant uses the PPDM data model and metadata tables to do something similar. Imagery, well spots, seismic lines and lease polygons are stacked in a map output that is in fact the last tab to the right of the browser. To the left are all the tabs to manage the many datasets a small operationg company or data repository will need to efficiently manage its assets. And only data models and metadata catalogs allowed to correctly structure years of document records management and geospatial information management. What I say last in fact comes first: users are guided through those details via pre-configured dropdown menus and tabs that mimic common workflows across the screen.

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