On 2012-01-25, at 10:06 AM, Becky Yoose wrote:
> - Dirty data issues when switching discovery layers or using legacy/vendor
> metadata (ex. HathiTrust)
I have a sharp recollection of a slide in a presentation Roy Tennant offered up at Access (at Halifax, maybe), where he offered up a range of dates extracted from an array of OAI harvested records. The good, the bad, the incomprehensible, the useless-without-context (01/02/03 anyone?) and on and on. In my years of migrating data, I've seen most of those variants. (except ones *intended* to be BCE).
Then there are the fielded data sets without authority control. My favourite example comes from staff who nominally worked for me, so I'm not telling tales out of school. The classic Dynix product had a Newspaper index module that we used before migrating it (PICK migrations; such a joy). One title had twenty variations on "Georgetown Independent" (I wish I was kidding) and the dates ranged from the early ninth century until nearly the 3rd millenium. (apparently there hasn't been much change in local council over the centuries).
I've come to the point where I hand-walk the spatial metadata to links with to geonames.org for the linked open data. Never had to do it for a set with more than 40,000 entries though. The good news is that it isn't hard to establish a valid additional entry when one is required.