What makes the feedback trustworthy

Each kind of feedback names where it came from, so you can check it.

Feedback	Comes from	How it is kept honest
“Start here: hole product_rule”	Ochiai ranking over the measured test-to-hole map	Each hole was opened alone in the reference and the full suite re-run; every plausible-but-wrong body must fail a test
JT003 ... mutates its argument	A checker rule on the JuliaSyntax tree	Every rule has positive, negative and two-correct-styles tests, an honest false-positive note and a 3-level hint ladder
“return type inferred as Fn…”	The compiler (Base.return_types) in a fresh process	Measured, never guessed; compared to the reference’s baseline
A lesson’s answer key	Running the snippet on Julia 1.10.13	tutor lessons verify re-runs every snippet; no other option may match

The site shows the same data the command-line tutor uses: lessons, rule metadata, the hole map and the explain reports are exported by tutor site-data, and the build fails if that export is stale. Your lesson progress on this site lives only in this browser.