You have to be careful what you measure. Imagine you have a 6th grader who is reading at a 2nd grade level. At the end of 6th grade you test her and find out no

You have to be careful what you measure. Imagine you have a 6th grader who is reading at a 2nd grade level. At the end of 6th grade you test her and find out now she's reading at a 5th grade level. Wow! A big improvement! Her teacher must be great. Unfortunately the test shows she's reading below grade level and the teacher is put on an improvement plan.