Any time you’ve got a big pile of stuff that you want to put out into the world — a list of your company’s products, a document archive for your intranet, or almost any set of content that goes into or comes out of a CMS — a sensible taxonomy will be crucial to your success, assuming you define success as “when people can actually find what they’re looking for.”

A good taxonomy is a win for both a company and its customers. It’s easy to see why taxonomy development is good for your users: The whole reason for creating a taxonomy for your site is to make information retrieval quick and easy by putting the information into a sensible structure that’s consistently applied. Well-designed taxonomies map out the base structure for your content, providing a navigation scheme that makes sense to your users.

Moreover, the taxonomies you develop can be deployed on multiple levels of your site: at the top levels, such as on sites like Yahoo! Or Ebay, where a strong taxonomy is the primary navigational tool, and also for deeper content, organizing the hundreds of products that your company makes or the thousands of documents you want to share on your intranet.  In the first example, a taxonomy is used to develop the overall site navigation, while the second example forms supplemental navigation to important information.

On the business side, by explicitly mapping out an organizational scheme for your company’s information, you outline a clear path for expanding the architecture of your site, showing you how new products, services, ideas, or documents fit into the larger picture of your company that you present to your customers on the Web. A good taxonomy provides your site with a robust, reusable structure that can be easily modified.  Without this, such additions often require lots of negotiation and can result in a haphazard patchwork that’s hard to use and maintain.

What Is a Taxonomy, Anyway?

If you’re anything like me when I got started on this subject, you’ve probably only got a vague idea about what a taxonomy actually is. Sure, you’ve seen some, and you know that hierarchy is involved, and possibly that indentation figures into it, but beyond that you’re not entirely sure how they work.

Here’s a simple, user-centered definition of taxonomy: It’s an explicit organizational scheme based on the relationships that exist between different pieces of information, related to a specific context. To build a taxonomy is to structure information so that it can be reliably accessed by anyone who needs access to that information within this context.

Some things are better explained by example:

Fruit
   Apples
      Golden Delicious
      Macintosh
      Granny Smith
   Oranges
      Navel
      Blood
      By State
         California
         Florida
   Kiwis
   Bananas

Easy, no? You’re familiar with fruit, so the relationships between the items listed are clear, and if you encountered this taxonomy exposed as a navigation scheme on your grocer’s Web site you wouldn’t have much difficulty browsing down to the bananas. This is the ideal situation: a well-organized set of terms that matches how your users think those terms ought to be organized.

Alas, it gets more complicated when you’re trying to work with niche information like your company’s product line:

Workstations
   Main boards/systems
      Motherboards
         A3x42 motherboard
         M2245 motherboard
         OEM A33df motherboard
         24601 motherboard
         Accelerated motherboards
            AX44334 motherboard
            AU PowerPerformance 94444 motherboard
            iWANTMI motherboard

Glazing over already, aren’t you? It happens. (I am indebted to taxonomist extraordinaire Amy J. Warner for this example.)

How Did It Get So Confusing So Quickly?

The difficulty with building an effective taxonomy lies in the level of detail required to create and maintain the data. It takes subject-specific knowledge to understand the inherent relationships among the different items that will make up the taxonomy, combined with the skill to articulate those relationships in a comprehensive, well-defined structure.

In most companies, this knowledge is likely spread out all over your organization, with many groups owning pieces of it — sales, product marketing, web site development, customer service. You may also find structures outside your organization that are relevant to your taxonomy, such as industry or trade standards, or hierarchies developed by your competition that your customers are already familiar with.

Gathering all of this information is a challenging job in itself, but putting it together can be even more difficult. Odds are that a lot of the information you find related to the taxonomy you’re developing will already have some sort of hierarchy, and it’s likely to be quite different than the one you’re developing. Different sets of the same information may even be in outright conflict with one another.

Maybe the marketing team organizes things primarily by manufacturer (Sunkist, Kraft), but the customer support department puts product category at the top-level (Fruit, Cheese). Neither is “wrong” — it might make sense for each to organize the company’s products as they do — but that doesn’t help when you’ve been tasked with putting all the information from each department together into one big, customer-facing beast. And sometimes, in an unpleasant political way, these groups are not all that willing to give up control of their little pieces to you.

Ready to Roll Your Own?

Given all this, you wouldn’t necessarily expect my next point, but believe me, it’s true: For most people (particularly the more business-y and design-y among us) developing a taxonomy is boring. Really mind-bogglingly boring. There’s just something about creating a long, highly organized list of stuff that makes the average person want to poke their eyes out with hot pointy sticks.  This doesn’t make it any less important, but it sure does make it that much more challenging to do properly.

And we haven’t even begun to delve into the nitty-gritty of taxonomy development, like how to develop alternative approaches to navigating the hierarchy, or what to do about synonyms, or what it takes to maintain a living, ever-changing taxonomy, or the many small but important issues that go into defining the hierarchy upon which rests the satisfaction of your customers and, quite possibly, the ultimate success of your business.

If, despite my grave warnings, you feel oddly compelled to gather words and organize them into definitive hierarchical schemes, then you’re probably part librarian. For you, we’ll provide some how-to information in a future essay (and for the rest of you, some outside resources to turn to for help.) So stay tuned.