When I'm assigning a tag to something (on flickr or del.icio.us), or even earlier when I'm thinking about what tag to use, I'm asking myself some of these questions:
- What is this thing?
- What is it about?
- Who is the writer or owner of this thing?
- Does it go into one of my special categories (first, ideas, toread)?
- What tags did others use for the same thing?
- If this is an index of other resources, what does it contain (articles, blogs)?
- If I want to find it later, what would I be looking for?
- What else is it like, and how did I tag those things?
- What category does it belong to, what type of thing is it, how would I classify it?
One problem is that until now, I didn't have this list handy, so my tags are inconsistent in meaning. I'm usually good about asking myself the first 4 questions (Note to self: there's something familiar about 4 questions...), and del.icio.us makes #5 easy by suggesting other tags, but the others are harder to remember. So maybe this list will help me gel my tags. But maybe the questions are in a descending order of meaning to me.
Another problem is that my intentions frequently collide and the same tag has multiple meanings. For example, I used the tag 'webapps' on an article about web applications, a list of webapps, and an actual web application. On further review, the actual web application isn't about webapps, it is a webapp, and aboutness is far more meaningful to me than classification. But maybe I used 'webapps' because that tag was in a list and I just selected it because it was close enough. After the fact, I want to separate the article and directory from an example.
One way to handle that is to give my tags some sort of tag. I like the way that del.icio.us indicates that you are tagging something for someone else, with the for: prefix and their id. That's very much like a namespace, and perhaps that the model to follow. So, I could start using about: to prefix tags that indicate aboutness, writer: or author: or owner: or by: to indicate the person or company who runs the thing, is: to indicate what it is, etc. In my case, I might consider about: to be the default namespace for my tags, and other types of tags would need a prefix. Then what would I do about a self-referential blog that's both about and by the same person or company.
So now there's another meme about machine tags, that are in the form of namespace:name=value. They look like a simple form of RDF but they're not quite the same thing. They seem to be a natural for geocoding, and the examples on flickr are just that. This idea might be too much for my immediate needs, but have some interesting possibilities as a format for post hoc metadata.