When experts talk about accountability under NCLB, they agree on one thing: The future lies in growth models. Discussions usually end there, never delving into the complexities of what makes a good growth model, how to design one, or whether they accomplish what NCLB sets out to do.
Charlie Barone jumps into the morass and reports on some of the technical problems and design flaws with Tennessee鈥檚 growth model. In for Education Sector, he writes that the Tennessee model doesn鈥檛 measure whether the state鈥檚 students are going to meet NCLB鈥檚 ultimate goal: universal proficiency by the 2013-14 school year. Instead, under the statistical methods in the Tennessee model, a student is considered proficient if he or she is on track to being proficient in three years, based on the trajectory of past test scores.
In short, proficiency is a 'moving target,' always three or more years away, in perpetuity. There is nothing to ensure that, over the long run, [a student] moves ahead toward a cumulatively higher level of performance over successive years.
The end result is that a school may make AYP in the 2014 even if 鈥渁 large proportion鈥� of students aren鈥檛 proficient, Barone writes.
LINKS:
On his blog, another point made in the Ed Sector report. 鈥淢ore statistical sophistication means less transparency,鈥� he writes there. He also calls out the statisticians who created the Tennessee model for failing to fully explain the mathematics behind it.
Ed Sector鈥檚 Zeno鈥檚 Paradox鈥� the mathematical theory that describes why a student could be considered proficient without ever getting there under a model that uses a three-year trajectory.
Oklahoma City teacher/blogger that the discussion of the paradox 鈥渃an offer no insight into what should be expected of a teacher in a high poverty neighborhood school.鈥�
Former teacher Tennessee鈥檚 growth model for favoring accuracy over simplicity.
For academic research on growth models, go to .
FINAL NOTE:
In a on my latest post on the Title I setaside, Barone light-heartedly complains that I reported that he wrote the administration 鈥渋s鈥� giving in to public school lobbyists. He actually wrote the administration 鈥渕ay鈥� be doing so. As someone who has fought over whether a law says grant recipients 鈥渟hall鈥� or 鈥渕ay鈥� do something, Barone understands the importance of word choice. I apologize for the error, and I thank him for being good-natured about it.
As long as I鈥檓 giving away links to Charlie鈥檚 blog, check out between him and Thompson on the Title I setasides. By the end, I was nodding my head, thinking 鈥淵eah, that was surreal.鈥�
