I also know what it's worth.
Two very different things....
I have a chunk of ambergris, found it years ago, and while briefly tempted to sell it, am grateful now I kept it.
I mostly forget about it, but now and again I walk through a cloud of its molecules and get briefly taken to, well, not sure where, some vague place of immeasurable joy.
In the literal sense.
You cannot measure the pleasure, the joy, the presence of the herenow that lump of aged whale shit brings.
The big data junkies among us might argue that all things are measurable, and I supposed you could take pre- and post-ambergris exposure levels of my serum oxytocin and plot them over time, but that becomes impractical.
Turns out measuring some pretty important things in education are impractical, too. Brilliant writing. Unorthodox but rational thinking. Sense of public duty. Joy. Ability to observe subtle details. Flexibility when confronted with new ideas. Empathy.
When our ability to measure outcomes trumps our choices of which outcomes matter, we've stripped "public" from education.
Tell the data junkies what you already know--not everything that matters can be reduced.