We can all agree that search engines like Google have really defined the way that we search for information on the internet. So the question is, why aren't we using Google to search for our geologic datasets? Do we have to do all that formal, structured metadata? What the hell is CSW anyways?
It acts as a proxy server. You ask it for http://metadata.usgin.org/record/a386a4ba-e892-11e0-9e4a-0024e880c1d2, and it reads that file identifier out and issues a CSW GetRecordByID request to a CSW server. The response to that CSW request is an XML document, and nobody (including Google) really cares about that, so the server formats the record as a very simple HTML page.
We write metadata so that we can search through it to find datasets we're interested in using for some purpose. I've recently started building a map-centric user-interface for doing this that has highlighted some simple functional requirements that metadata should meet in order to be helpful in accomplishing the task.
What I've done here is essentially listed the conceptual elements that seem neccessary in order to make a functional user-interface for searching. This has nothing to do with metadata syntax, just with metadata concepts.