#VAM: Explain this to me please.

Here’s some specifics:

My final appraisal for the 2011-2012 school year:

Evaluation summary scores:
Lesson Study: 100/100 points x .20 (20%) = 20 points
Principal Appraisal: 88/100 points x .40 (40%) = 35.2 points
VAM Data: 10/100 x .40 (40%) = 4 points

Total points = 59.2 (Unsatisfactory)

The VAM data comes from Alachua Elementary School’s FCAT scores; children I NEVER taught, although my opinion wouldn’t be different even if I had.

I keep asking people to explain this to me because no one ever takes me up on it. Why? It’s incomprehensible.