[Sigia-l] Expandable navigation

[Joy Ray]

Hi, 

Can anyone point me to studies (or offer opinion/observations) about how
many levels are "too much" for an expandable left navigation column?  

My gut is telling me 3 levels maximum (with additional sub-nav placed
elsewhere) but I don't really have anything concrete to back this up.

Thoughts? 

(Example of what I'm talking about, this has 4 levels...by the way, the
"real life" nav items would be considerably more complex, lengthy, and would
probably wrap)

> FRUIT
--> Apples
----v Red
------- Gala
------- Red Delicious
----> Green
--> Oranges
--> Bananas

> VEGETABLES

> MEAT


Thanks!

Joy