Indeed. And the other drawback of hierarchical organisation is that you can only present the structure from one viewpoint. In other words, if your subject matter has regional content (for example) plus seasonal content do you organise your hierarchy first into Americas, Asia, EMEA and then each chapter into Spring, Summer, Autumn, Winter. It would be equally valid to do it the other way round (season first then region). Neither is useful unless the reader knows what to expect.

The depth of the hierarchy generally reflects the number of dimensions in play. The authors will often find the same sub-headings repeated in many different chapters.

With online material we have other options: to present all dimensions as options with equal weight (a Season radio button and a Region radio button), or for a more general solution we could simply enable search and have a Google-style interface to the material.

If the search is backed up by a genuinely useful index that reflects the many variations allowed by the content's language (do I search for Fall or Autumn for example) then this solution is often usable.

What can help enormously is to allow the content to be tagged by its consumers. Then the index becomes more useful over time as people find the text they are looking for and flag it using a term that is meaningful to them. This technique contains a positive feedback mechanism that eventually takes account of common spelling mistakes and other "errors" simply by leveraging the fact that previous readers have made the same mistakes.

People are experimenting with "tag clouds" and other devices for portraying this information. It will be intersting to see what standards emerge over time.

-- Dominic Sayers (email)

Dominic says:

"And the other drawback of hierarchical organisation is that you can only present the structure from one viewpoint."

While I'll admit that this is a drawback, one must keep in mind that all information is hierarchical in one way or another. Without links between random facts, we have no method to expand our understanding of a subject. We can't learn about new species of cats, for example, without grouping together what we all know, and adding to it.

Hierarchies cannot be dismissed entirely. Organization depends on it. Sentences and paragraphs form a low level hierarchy that seems to be absent in this conversation. Although too many levels of organization confuse the reader/user, a certain level is necessary to present information in a clear manner. Defining the correct level is the true goal of the presenter, and I believe that may change depending on the audience, and type of information.

I'm not trying to claim that Dominic, or anyone else, is suggesting we do away with hierarchies altogether. But neither do I agree that allowing the reader to redefine the author's hierarchies is a good thing. Good writing should be looked upon as presenting an argument. Sometimes the argument is straight-forward (i.e, testing was conducted in a defined manner and the result are within predefined parameters), and many times it is not (pick any political argument). The organizational scheme of the document can influence the effectiveness of the rhetoric, for instance, allowing an unwary user to take the test methodology out of context, and thereby attempting to invalidate the data.

-- Mike Rossiter (email)

Hierarchies do have their uses. They are a useful meta-index to large collections of related but individually self-contained articles or pieces of information. Good examples are the statutes or laws of a nation or region, an encyclopedia, a linnean guide to species and a library. All of these have hierarchical structures which provide a means to find relevant information.

However these are essentially reference works - i.e. you know what information you need (that you don't have) and you need to find it quickly. Users guides introduce you to many things you don't know (and don't know that you don't know) and excessive hierarchical organisation just gets in the way of reading and understanding the guide as a whole. There are drawbacks to less headings however and that is it's difficult to find things again because you have fewer guidelines to find them - indexes are not as good in these days of automation and are rarely good for figures and diagrams (what ever happened to the old fashioned table of figures). So for books to be read and understood, hierarchy = poor to bad; for reference works and collections, hierarchy = OK to good.

-- John Walker (email)

I'm looking for examples of websites with good hierarchies. Here is one:

http://www.apple.com/sitemap/

Can anyone recommend any others?

-- Michael Cusack (email)