Comparing Apples to Apples?

                 

Engage N.Y. made a seven minute video attempting to explain growth scores.  I watched it months ago.  Soon, this system will become a reality.  Statistically-driven reformers rest false hopes in the legitimacy of measurements of student growth percentiles (SGP) to judge teachers by mean growth percentiles (MGP).  What a MGP--Misguided Group of People!

Some self-satisfied someone must be smirking in his office over his model of statistical analysis.  The model seeks to sort students by levels of affluence or poverty, learning disabilities, language deficiencies, among other things which EngageNY fails to mention.  It is purposefully vague.  We are assured though that "apples" are not being compared  to "oranges." 

Even if they are dead sure, however, they are dealing only with apples, I still dispute their claims.  Two children living in the same household, let us say twins or even clones, with the same learning and language capabilities, are not the same person.  They will not perform identically even in the same classroom with the same teacher.  It would be insulting to think so.  There are so many other factors for which all the mathematical formulas in the world can never account.    

The events in one child's life may completely change a child's performance from one year to the next.   One student may improve in history, but it may stem from actions by his English teacher or another individual completely outside the framework of school.  In the same manner, another student may see his test scores drop for reasons over which the teacher has absolutely no control.  Do statisticians with their complex formulas hope to overwhelm us into believing that their calculations are anything more than simpletons parading around as kings?  Do their complex formulas blind them to common sense?

While we're talking about apples, let me conclude by observing that right now teachers seem to be the apples corporate reformers are aiming to shoot off public education's head.