Hi Perian- > 1) You have objects. You apply vocabularies to the objects in > order to describe them. The vocabularies facilitate how your > object information is seen by other computers. Examples of > Vocabularies are: AAT, ULAN, Chenhall's > > (I understand #1 pretty well. Here's where I start to get lost...)
Yep, you're right on target here. > 2) In order for the other computers to understand what you're > giving them, the information needs to be arranged in a > specific way. These are the element sets...? these are MARC, > LOC, VRA, Dublin Core The element sets provide the "buckets" (fields) into which the vocabulary terms you've chosen go. They also generally have buckets for bits of information that a controlled vocabulary doesn't necessarily cover, such as dimensions of an art work. All of the relevant elements together form one metadata record for the item. These standards are sometimes called element sets, or data structure standards. I'd take "LOC" off of this list. If you're referring to the Library of Congress Subject Headings, those go in #1, with AAT, etc. > 3) Because very few institutions have "pure" collections that > fit into one of the Vocabularies, we can use multiple > Vocabularies. Do we use multiples of #2 as well? These are > defined and plugged into the element sets. They are tagged as > belonging to a specific Vocabulary You don't need separate records when you are using more than one vocabulary to describe your items. More robust (or complicated, depending on your perspective) metadata structure standards allow you to specify the controlled vocabulary used for individual elements for which it's likely a controlled vocabulary will be used. Most don't require one is used at all or specify which one, but when you do use one you can often say which one you did use. For example, in CDWA Lite, the subjectTerm element has a termsource attribute in which you say which vocabulary the value came from. MODS in the library world has similar functions. But not all metadata structure standards provide this capability. Simple Dublin Core (the 15 element set, without qualifiers) provides no way to say what vocabulary an entry came from. Qualified Dublin Core adds this capability for subjects. > (I think there's a middle piece in here I'm missing) I think the missing piece in here is use of this date for local retrieval. In your local environment, you can control the data and the assumptions made about it. So even if you're using a data structure standard that doesn't let you say which vocabulary is used for a given field, if you always use the same one, you know that and can correct for it. This isn't as easy in the shared environment. In your local system, you probably will have some (but maybe small) level of control over how this data displays to the user - which fields show, etc. > 4) There is an umbrella structure, the Harvester, which can > read #2 and serve it to the user in readable form. Examples: > OAI, MARC (also fits as a #2), XML I think the label for what you're getting at here is protocols for metadata sharing. The "harvester" (an OAI term noting a service that comes and gets your metadata to pool it together with metadata from other institutions) facilitates one-stop searching of resources from multiple places. I think what's important here is that there are a number of protocols which promote metadata sharing. OAI is one of them, that operates on the harvesting model, pre-fetching metadata before searches happen. Z39.50 and SRU are other protocols, that operate on a federated searching model where a user query is simultaneously sent to multiple places and the results are then aggregated for display to the user. All of these are specifications for how the communication between you with the interesting resources and the aggregator who provides multi-collection searching works. They define *how* the metadata you have gets from you to the aggregator. So OAI is a *protocol*, not a metadata format. MARC is a metadata format used in libraries both for local systems and for sharing, so it goes in both #4 and the in-between step before it. XML is simply a meta-language that allows you to specify data structure standards like those in #2 above. Hope this helps! Jenn ======================== Jenn Riley Metadata Librarian Digital Library Program Indiana University - Bloomington Wells Library E170 (812) 856-5759 www.dlib.indiana.edu Inquiring Librarian blog: www.inquiringlibrarian.blogspot.com
