The grade of mutaba‘ah depends on where the supporting route joins the chain:
1. Complete mutaba‘ah (tamma): another transmitter reports from the very same teacher as the narrator whose singularity is being tested.
2. Partial mutaba‘ah (qasira): the two paths meet at a higher link—above that teacher—or reach the same Companion through other intermediaries.
Both may strengthen an account, but not in precisely the same way. Direct confirmation from the same teacher refutes the suspected exclusivity at that link, whereas a higher meeting supplies more indirect corroboration.
Important limit: complete versus partial names the *position* of agreement; it does not independently grade either chain as sound.