[dferr]

The TDD analogy works when youre trying to objectively quantify and rank a person, based on their test result, but i don't think it works as well when youre trying to test a student body, or more roboticly put, a body of objects(really, thats not so TDD as much as it is ranking outputs of a black box)

When it comes to testing teacher/school performance through its students, if you reconsider a test framework is given a body of objects:

* instantiated outside its control(students are brought, not created at school)

* instantiated with unique and unknown inputs(vs given known inputs)

* have hidden independent variables(personal traits)

* have hidden linked/shared variables(external traits, economic environment, local crime, family etc)

* have _few known inputs_ (teachers, school staff, grounds)

and then ONLY test pass/fail based on those _few known inputs_ and the results from each individual object, you will learn that the inputs pass/failed, but determining what the cause is will be far harder(strong linked variable or teacher? intelligence sapping virus?). unfortunately the frameworks executors believe that the tests clearly show that given the inputs they control, the results are repeatable.

I don't think testing a body of objects-- err --students is pointless, but directly linking their results to teachers and schools discounts so much more than this testing framework can account for. They should be a starting place for conversation, but not a litmus test.