I have a confession to make. For most of my teaching career, I've drawn lines in the sand, jumped on soapboxes, and in some cases thrown time-out-worthy temper tantrums about data. My students cannot be reduced to numbers. What do you want me to do, count the number of adjectives they use in an essay to show their performance? Reading and writing are both so very complex that they cannot be reduced to a string of numbers.
That's not the confession. The confession is this: I have reduced my students to a series of numbers. Not just numbers, color coded ones in an Excel spreadsheet. And (deep breath), I like it. It has actually made me a better teacher for them.