Website File Structure - SEO question

[[AJ]]

Does anyone know what the current 'done thing' is with website file structures? Articles I have read in the past encourage file structures to be as flat as possible. However, more and more websites appear to be splitting their sites up into sub folders. Is this now encouraged for search engine optimisation and if so, are underscores (_) treated the same as hyphens (-) these days? I appreciate that any sub folder names should be meaningful, but is it better to have www.domain.com/descriptive/ rather than www.domain.com/descriptive.html?

I have googled about a bit and there appears still be some conflicting opinion, I just thought I'd see what the PH lot think!

[telford_mike]

You have to have some sort of a structure or it all becomes too much of a nightmare. I try to keep mine to 2 levels for the html though. Stuff like graphics and download items can be buried as deep as you like.

[JohnnyPanic]

It really depends on the size of the site. If it's just a dozen pages or so then flat is fine, but if you have quite a few pages in various sections then I'd put them in folders.

At the last check Google doesn't count '_' as a word delimiter in URLs in the same way that it does a '-'.

So for a bigger site you could go for:
ilikecheese.com/blue-cheese/danish-blue.htm

But if it's a small site and there a no sub-pages under 'blue cheese' then go for:
ilikecheese.com/blue-cheese.htm

[miniman]

Preferable to omit the actual filename - i.e. /blue-cheese/ rather than /blue-cheese.html - most CMS systems will do this automatically.

[Rockatansky]

From slide 9 of this Matt Cutts presentation:

1. Keywords in url paths: domain.com/my-words

* Dashes are best
* Next best is underscores
* No spaces is worst

[10JH]

Might be worth asking PHer Dick Dastardly, he is an SEO expert and may be able to help with this or if you need to hire someone for your site to help with it.

[[AJ]]

Thanks for the advice guys. The site is medium sized, a couple hundred pages in total. I have decided to split up some of the main sections, but keep the file structure to just 2 levels deep.