Would it not be best to have a dynamic system but one that re-writes URLs to “show” a friendlier structure. The architecture can be as flat as you like but she’d still look pretty.

Chris Whyles

–Sean Ruiz

* http://www.google.com/support/webmasters/bin/answer.py?hl=en&answer=76329

While I agree that a site like twitter doesn’t really confirm to this approach, it is still very solid SEO for 90% of larger sites to build URLs based on a hierarchical IA.

1. Google scrapes breadcrumbs from links, not from directory structures in URIs. For example Google can perfectly understand a path to the root on a page with a query string like ?category=widgets&state=ny&country=us, or even /item=11, provided there’s a meaningful breadcrumb navigation given on this page. Breadcrumbs describe a default navigation path (back to the root, usually), regardless whether there’s a hierarchy or not. Often there’s more than one logical way from the root to a particular page. That’s why setting one of many possible paths in stone is a bad idea.
2. When you put that as a SOP, it’s simply not true. As long as there’s a hierarchy in real life, then it can make sense, but there are more ways to implement it than pseudo file system hierarchies. Lots of things in real life aren’t organized in natural hierarchies, though. Artificial hierarchies aren’t helpful, esp. not in analytics.
3. If that would be true, you could provide me with a model to organize all Twitter users in a hierarchy. You can’t do that.
4. The opposite is true. When you have to move content, it helps when the content isn’t organized in a hierarchy that has impact on navigation and whatnot. I agree that a solid IA helps, but a solid IA is an IA that doesn’t rely on (artificial) hierarchies, but works with networks of intermeshed nodes and similar concepts instead.
5. A URI like /tom-clancy-all-titles is way more meaningful, more useful, more bookmarker friendly… than /books/authors/us/clancy-tom/titles/all. The page served from /tom-clancy-all-titles can very well have a breadcrumb navigation like Books:Authors:USA:Tom Clancy:All titles.

I have to disagree with you for several reasons.
1. Google is now displaying breadcrumbs in SERP and they are more likely to do so based on hierarchies.
2. Hierarchically designed IA makes it MUCH easier to analyze indexation and web traffic.
3. While internal linking structures are clearly driving SERP, it is much easier to understand and visualize your internal linking structures if you have a hierarchical structure.
4. Someday, you may need to move some content around or do other tricky and inconvenient things. You will thank yourself if you took the time to build out a really solid IA first.
5. Believe it or not, some users do see the URL and it helps establish information scent.

Having everything “flat”, that is the URI’s path identifies the resource without using slashes, is an option, and just that. You can do it, combine it with slash delimited paths, query strings, … whatever. Always do what’s best for the actual site, and don’t listen to crappy advice that tells you otherwise, even when it comes from a major search engine and is beginner level stuff trying to bring a first understanding of what information architecture is to the noobs.

Just bear in mind that neither search engines nor human vistors care much about your URIs - they follow links, and only links. So if it’s difficult to create a hierarchical structure (usually it’s raping common sense at some point), then don’t do it, or do it just for parts of your content where it makes sense.

are you advocating everything being flat 1 tier?

whats the benefits of this?

Theres no doubt that sites like the bbc make good use of folder like structures??

so what do you think about the best practice?