Kudos to the Gates Foundation, seriously: after spending $775m on the Intensive Partnerships for Effective Teaching, a Big Data initiative to improve education for poor and disadvantaged students, they hired outside auditors to evaluate the program’s effectiveness, and published that report, even though it shows that the approach did no good on balance and arguably caused real harms to teachers and students.
Cathy “Weapons of Math Destruction” O'Neil has given the report a close reading, and she found that the problems with the approach were pretty predictable: asking principals to rate teachers produces pretty uniform and meaningless five-star results, while the “value add” algorithms that are supposed to figure out how much of a student’s performance is attributable to a teacher are basically random number generators.
The result was a hugely stressful (and sometimes career-destroying) exercise in which teachers and students were human guinea pigs in an experiment that could have been evaluated more cheaply and quickly in smaller laboratory tests before it was unleashed on whole populations.
