lucy24 - 11:45 pm on Nov 27, 2011 (gmt 0)
... and don't ask them if they understood it. Ask them to tell you in their own words what it says. You don't want to know if they say they understood it, you want to know if they did understand it.*
* "Do you understand these rights as they have been read to you?" There are at least three groups of people who would truthfully answer No-- and two of those groups will answer Yes.