Namespaces for Tags

I've been thinking about "namespaces" for tags lately. Sometimes tags become too random, disorganized, or numerous to be relevant or useful. One way of cutting through the clutter is to create more than one set of tags. I've seen this on at least one website, sprig.org, which offers "togs" or an alternative set of tags to classify posts by. The difference is these tags are restricted to a particular concept, types of ecology-related terms, such as "organic." What this secondary set of tags produces is in reality a set of tags under another namespace "Ecology."

It is possible to organize tags into namespaces, each representing a concept. This would not be imposing hierarchy on tags, but creating nodes representing concepts. So that Ecology might contain organic, carbon free, sustainable, etc. and Mathematics might contain number, equation, factor, etc.

I organize my photographs in Photoshop Elements using tags. I chose to avoid using tags like categories and instead only create tags for qualities of the image. I try to create tags that describe the image the way an art historian might classify works by their elements or an archivist might classify images according to social use. An image depicting people at work is an "occupational" for example. A painting might be "abstract" and "nature" and "patterns."

Here is a partial list of my tags. I try to create tags for

a) Qualities of art, such as Landscape or Pictorialist
b) Things that can be seen in photographs, concrete like Aircraft or abstract like Patterns
c) Subjects, categories of subjects, concrete like Nature, Sky or abstract like Time


Abstract
Aircraft
Automobile
Birds
Butterflies
Concrete
Flowers
Impressionist
Landscape
Leaves
Nature
Patterns
Photos
Pictorialist
Plants
Rain
Shadows
Sky
Snow
Time
Trees
Urban

I can see some benefit in putting these in a namespace, limiting the tags in this space to reduce clutter. For example, tags on Buddhism would not be found in great number in this set (unless a) you have a lot of Buddhist photography or b) you attach tags from a Buddhist namespace and then they wouldn't be in the set). I don't know how successful namespaces might be for tagging. Programmers love namespaces, but ordinary people find them confusing. I like the idea of tying namespaces to concepts.

I think namespaces would come in handy when choosing tags from a list, like when you show all labels in Blogger's interface. You get one long unreadable list of every tag you've used. Sometimes I love tags when I can just enter the key words that are in my mind while writing a post, but sometimes I hate them when what I really want are categories. I read an article the other day by a graphic artist who designs for the web who continued to use the web safe palette long after it was not technically necessary. He argued that artists tend to choose colors from a comprehensible and memorable palette of colors, such as the Pantone set or the set of colors defined by the various oil pigments. With 16 million colors there are far more colors than anyone could recall or discern. For every "olive green" there are hundreds of colors in between that and the next discernible color moving in either direction on the color wheel. It helps to have a standard color when envisioning or communicating "olive green" to others. I think tags are afflicted with this problem.