Testing Checkpoint 6.1 of WCAG 1.0: Style sheets

Hello,

I am new to this mailing list and I hope that this may be an appropriate place to inquire about data collection for a master's thesis on web accessibility.

I would like to compare the accessibility of a number of sites, and one of the checkpoints that I will be discussing is 6.1: Documents should be readable without style sheets.  

Would anyone have a suggestion for an evaluation tool that highlights the number of errors (or potential errors) for this checkpoint and their locations in a web site?  Is there a recommended procedure for checking compliance with this checkpoint?

Your assistance would be most appreciated.

Sincerely,
Annmarie