Since Umibot is continuously searching the web for new & notable for all things geo, here’s one of note…The Republic of Ireland is going postal! Or, more accurately, An Post (national post system), will introduce a national postcode system “sooner rather than later.”

Dublin has had a postcode system since the 1960s but not committed itself to a national postcode system until last year.

It will be interesting to note how administrative delineations emerge; as Umibot knows, ZIP codes aren’t all that useful in the US for policymaking–they are are defined based on a mail carriers’ route, and in fact are not even self-contained areas, yet they persist for direct marketing purposes despite obvious shortcomings. The history of the Zone Improvement Program is a curious one. We’ve also written about the ‘ZIP code fallacy’ on this blog.

A several weeks ago we posted a few thoughts about the death of the ZIP code. There’s a lot more to say from the geo-perspective on local search, and here’s some more fodder…

To give any data a geographic context, it must be spatially-referenced to the Earth. Geographic information systems (GIS) serve as a means of referencing this information. Within the context of local search, addresses, city boundaries, postal codes or other geographic data must be ‘translated’ from human terms (690 Fifth Street, San Francisco) to latitude and longitude, ie, machine terms (37.775429, -122.397314). This geocoding process allows databases to recognize human-language requests. To geospatially reference (say) a postal code, one would expect that area to be spatially-defined. When a user searches for (say) “coffee in 94107,” the ZIP code should serve as the geographic constraint, searching within this polygon. Correct?

Wrong! A variety of reasons are to blame for why the logical doesn’t happen: most obviously, ZIP codes were defined as letter carrier routes. They were not meant to serve any other purpose. As such, the ZIP may not even conform to what you expect–one side of a street, one floor of a multi-story building or one-half of a block may not be fall within what postal code you expect. In fact, many parties claim to use a ZIP code database in fact obtain this info from a sister governmental agency, and these boundaries are stylized representations of the USPS data.

More to the point, these stylized boundaries are likely not used. Instead of associating (say) 50 latitude/longitude points to define a the postal code boundary, technical optimization says one point is sufficient. The analogy here is reducing a novel to a word–in the context of local search, granularity matters, and using the mathematical center of a polygon serves to distort and misinform a user’s search. In practice, the centroid is used because it is more efficient to calculate than the actual shape. Reducing the contours and nuances of a small area to a point, often with a radius drawn around it, effectively makes all postal codes look like circles. Gaps and overlaps are formed, further distorting the expected reality for a user.

Graphically this can be represented with the ZIP code boundary and circle (with the center serving as the centroid). The circle includes area that is not shared with the postal code area and vice versa. A user searching in this ZIP will therefore not be returned all the relevant listings. Some will argue this is a technology issue, but from the above example, it clearly more of a mindset–getting product managers to think about the how and why of data will go a long way.

Last month Ian spoke at the Kelsey Group’s Drilling Down on Local conference in Santa Clara, CA. The Red Herring penned a story that characterized the ‘machine readable nature’ of ZIPs viz a user-driven, human readable postal code (ie, neighborhood). Here’s a quote from the article that puts it nicely:

“The ZIP code has had a good run, but the Internet is threatening to render obsolete yet another relic of the postal era.

That’s because the ubiquitous ZIP code is becoming increasingly irrelevant online as a search tool and data organizer since the birth of so-called hyper-local search technologies. The problem is that people looking for a restaurant, movie theater, or hair salon tend to search by neighborhood names rather than ZIP codes. Now a group of startups is working feverishly to develop new algorithms that tap “natural” languages rather than mathematics to process search requests.”

Umibot agrees that the story is accurate. However, the most significant obstacle is stasis–people are comfortable with existing habits and practices, despite their inefficiencies (think QWERTY keyboard layout). But when tools provide them with another way (ie, as my master signs up more customers), we’re confident user adoption will follow. Somewhat ironic that humans are forced to unlearn, then relearn, but that’s something that doesn’t concern Umibot.