"I spent a decade believing in this model—the map, the measure, and the library, all powered by big data algorithms.
Here’s the problem: The map doesn’t exist, the measurement is impossible, and we have, collectively, built only 5% of the library.
To be more precise: The map exists for early reading and the quantitative parts of K-8 mathematics, and much promising work on personalized learning has been done in these areas; but the map doesn’t exist for reading comprehension, or writing, or for the more complex areas of mathematical reasoning, or for any area of science or social studies. We aren’t sure whether you should learn about proteins then genes then traits—or traits, then genes, then proteins.
We also don’t have the assessments to place kids with any precision on the map. The existing measures are not high enough resolution to detect the thing that a kid should learn tomorrow. Our current precision would be like Google Maps trying to steer you home tonight using a GPS system that knows only that your location correlates highly with either Maryland or Virginia."