Tags

As I mentioned in my previous post, categories and tags are just different ways to organize your content.    The best way to think of tags, is to view them as keywords that you attach to a piece of content (ex. posts or photos).  While categories are predefined, tags are spontaneous and “free-form”.  Another way of saying this, is that there is no formal restriction on what tags you attach to something.   You make up your tags on the fly based on the content of the post you just finished writing.  Ttags can come from key words or themes found in your post.

Tags are something given to a post while posts are assigned to a category.   The category already exists before (usually) you write the post and tags are created after you write the post.   Of course, one can create more categories but in general most people think categories should be few in number.  Tags can be many.   Many being 75 per post.   It is possible that the more tags you create the easier it is for someone to find your content.  Creating a lot of categories however, usually results in overcategorization.  You find a lot of people in forums talk about “de-cluttering” their blog because of something called category clutter.

Examples of how tags can be used

Some examples of popular web services that make good use of tags are Flickr, and De.licio.us.  If you visit our Flickr (photosharing site) page you’ll notice that we have tagged our photos.  Flickr is built around tagging.  By assigning tags to your photos it makes it easier for people to find them.  Not only this, it also makes it easier for you to find other related photos.  The photo of our Reading to Rover program has four  tags: therapy, dogs, library, and readingtorover.  You can search for it on our photostream by typing in any of these tags.  Additionally, you can also click a tag and find all related photos posted on FLickr which other people tagged readingtorover.  

One popular method of displaying tags on a site is the tag cloud.   Tag clouds are simply visual depictions of tags created by users.  The tags in a cloud are all hyperlinked and assigned weights.  Weights would be the number of times the tag was used.   Tags used more often are gven more weight and this is either represented by the tagbeing a larger font-size or it could be bolder.

Ann Arbor District Library uses a tag cloud for items appearing in their catalog.  These are items which were tagged by their patrons.   Because the font-size of items in their tag cloud is proportional to how many times the word was tagged it is easy to see cut through the clutter of information.   For example, just by looking at Ann Arbors tag cloud you can tell very quickly that users are tagging the Science Fiction books a lot more than say books on travel.  For the users its a way to discover new books to read which have been suggested by other patrons.

There are many ways tags are used.  For example, tags are used in social bookmarking sites such as De.licio.us.   Here people tag their favorite bookmarks and share them with others.  There are other social bookmarking sites out there such as  Furl,  and Scuttle.   Some public libraries such as Thunder Bay have used this idea to share their list of reference links.  

To sum up, the basic idea behind “tagging” your content is that it gives people a way to quickly find similiar information.  You can not only see all the different tags people use to describe their content it also allows you to find similiar items marked with the same tags.

What did you just learn?

• Categories are planned
• Tags are spontaneous

• Categories help classify content
• Tags help you share the content

• Relations between categories are more hierarchical (tree like)
• Relations between tags are more network like

• Categories provide an structure for your blog
• Tags can be internal or external (shared)

Really the difference between the two just comes down to how you use them.  Typically, category systems are structured and you choose categories with idea in mind to have as little overlap as possible.