Where each list comes from, how a site is graded and ranked, and what a table does not tell you.
The lists
Universities. The members of Ivy League, Big Ten, SEC, ACC, Big 12, Pac-12, Big East, taken from the full-members table of each conference's Wikipedia article. The exact article revisions are stored with the list. A university is the registrable domain of its official website (cs.example.edu and www.example.edu both count as example.edu), from Wikidata's "official website" property; two had none and were set by hand after loading the site.
State governments. One portal per state: the official website on the state's Wikidata record, or, where that is missing, the state's own entry in the federal .gov registry (CISA's dotgov-data). Two were corrected by hand where the recorded address was out of date.
Nothing is added to fill a gap. A group is as large as its source says. If you think an entry is wrong, the lists are plain files in the open repository.
The grade
The same measurement as every page on this site, from the same job that grades the top 1,000: the website and www must answer over IPv6, mail servers need AAAA records, and at least one nameserver does. See the full method. Only the main domain is graded, not every department's or agency's site.
The rank
Sites are ordered by grade, A first. Equal grades share a rank, because the grade is coarse; there is no tie-breaker that would mean anything.
Within a group, the rank is among the sites graded. A site with no usable result yet, or whose newest result is more than eight days old, is shown without a rank.
An F is ranked only after probes on other continents also fail to connect to the site. Until then the site shows as "confirming".
Conferences are ordered by the share of their ranked members with an A; ties go to the larger share of B, then C, and so on.
Changes
Every site is re-checked weekly and every result is kept. A site that changes grade, or gains or loses IPv6, appears in the changes feed at its next check.
What this does not tell you
It is one measurement, from one place, of one domain per institution. It says nothing about how good a university or a state government is.
A grade below A can be a mail provider or DNS host choice made years ago. It describes the setup, not the people.
Our server's IPv6 can have its own problems; when it does, a site is reported as "couldn't test", never as failing.