"I can" sheets

Our classes are using "I can" sheets: these are filled out at the beginning of the unit and list the important standards for the unit (eg, I can represent a function in an equation, table, words, or graph).  Students self-evaluate themselves on how well they can do each standard on a scale of 1 (I don't know what this means) to 5 (I know this so well I could teach this to the class).  At the beginning of the unit, most of the standards are closer to 1's and 2's.  However, in algebra, many of the students put down 4 or 5 for "I can recognize independent and dependent variables."  Apparently, science classes have been stressing that, and it showed up in math.  After teaching for 2/3 of the unit, we gave the "I can" sheets back to students, asking them to fill them out again for the same standards.  Most of the students now have 4's and 5's.  What I like about the "I can" sheets is the ability to quickly scan the pages and identify students who are still unclear on important concepts.  This enables me to approach them individually and encourage them to come in afterschool or during tutorial in order to help them succeed.  If several students are still unclear on one particular standard, I can reteach that concept in the next lesson.