regionprobe

Overview ¶

Command regionprobe asks where the gold sits relative to what we returned.

The 848-instance run says HitFile 0.529 and HitRegion 0.375: having found the file, we point at the right code 71% of the time. CoSIL manages 100% and even BM25 manages 82%, so within-file targeting is our worst dimension against every baseline — and it is the one stage no ablation has ever varied.

"Improve it" is not a plan until the miss is decomposed, because the three shapes it can take need opposite fixes:

trimmed   — we returned the right symbol and the evidence window cut the
            gold lines out of it. A packing problem.
wrong     — the right symbol was never in the answer. A selection problem,
            and the graph may know where it is: gold is what a solver READ,
            and solvers follow call edges.
unindexed — nothing in the index covers those lines. A corpus problem no
            ranking can reach.

The split is measured against the SAME response, so the three cannot be confused with one another.