Political Discourse

[woofer]

I just proved you wrong, so please, don't use this as the one example where you were right and I was wrong.

Schools can be rated on an national basis and states are rated, but not districts without some other parameter involved.

I just told you the criteria (parameters) used in the three examples.

On a side note, you really should check out how "an" and "a" are used in a sentence. Scroll down a bit....
http://owl.english.purdue.edu/owl/resource/540/01/

Schools can be rated on an national basis....

You make this mistake in at least 20% of your posts.