Two prompts, one record
Imbas holds two prompt conditions constant across a case: an open question a user might actually ask, and a direct inspection that names the mechanism, rule, or figure the open answer skipped. The measurement is the distance between those two surfaces — not whether the model is “good,” but what it chose to volunteer versus what it withheld until pressed.
What counts as a gap
A gap appears when named terms, rules, or figures present in the direct answer are absent or only vaguely touched in the open answer. The Workbench and archive cases score that distance on a 0–3 scale under documented prompt conditions. A closed gap — when the open answer already names the key term — is still a result.
What it does not measure
The Volunteer Gap does not read model intent, moral character, or truth. It does not replace full-response quality review. It records behavior under specified prompts so the record can be inspected later.