A single number, institution or pattern, with its evidence and its limits. Every note has a permanent address so it can be cited, checked and argued with.
Polk County contracted a private microschool founded by two teachers who had left a Polk County public school. The Index has coded 21 Florida institutions and found no education-school program built for this sector. Both facts describe the same state in the same year.
District participation in Florida's part-time scholarship marketplace went from roughly one in three to about 75% of 67 districts in twelve months. Texas districts, offered state money for a comparable arrangement, mostly declined. The contrast is the finding.
Coding North and South America turned up a mechanism the school-choice literature barely names: public money paid not per pupil, but against a private school's teaching payroll. Five systems in this hemisphere work that way.
A 2021 law let Florida colleges sponsor charter schools. Four institutions now do. We had coded one of them "nothing found" — because we read its course roster and stopped.
Every other null in the Index records an institution that never built for this sector. Nova Southeastern built one and no longer offers it — documented in the university's own archive.
Michigan is the deepest university-charter ecosystem in the country. All eight public university authorizers are now coded. Between them they hold well over 200 schools and exactly one preparation program.
Demand is measured. Policy adoption is measured. Preparation quality is measured. Whether the workforce exists to staff what policy enables falls between every organization in the field.
Most confirmed university entries into the choice sector took the form of running or authorizing a school rather than building a degree. A catalog scan would miss all of them.
87% of teachers feel prepared to teach in a district school. 34% feel prepared for a microschool — the sector now serving more than 750,000 children.
Field Notes are free to read, quote and cite. Every one carries its sources and the date each was checked.