For example, there is this piece of inconsistency in the OpenAM Policy Editor implementation.
To add a resource, it's fairly simple.
Step 1: Roll over the mouse on "Available patterns". A green arrow appears. Click on the arrow.
Step 2: On the right-hand side, a "+" appears. Click on it and it will add the pattern to the resource. Simple!
If you want to remove the pattern, a "X" is available to carry out the function. Intuitive.
Now, the UI experience for Define Subject Conditions and Define Environment Conditions is not consistent with the previous experience.
For example, to add a subject type, one has to drag the grey bar to the green area. (I missed this totally when I first used this XUI policy editor)
Where is the "+" to add?
Now, to remove a subject condition, one has to click on the "rubbish bin" icon, instead of "X" which was used in Resources.
Both "rubbish bin" and "X" serve the same function perfectly. However, in a product (especially within the same Policy Editor), one would expect the UI experience to be consistent throughout.
Kind of weird to me.
If I were to implement such a UI, I would have failed my Human-Computer Interaction course badly many years back in the University. I had a strict lecturer then. :)