MWITA-AE-2026-006 · Evidence A · P1
The 2025 IAB commerce-media guidance centers credible counterfactuals, bias control and separation of signal from noise as three principles for incrementality measurement.
What this does not establish
A reported attributed conversion is not incremental without a defensible counterfactual.
Counterevidence & uncertainty
Interference and selection can remain even with a nominal control group.
What would change the reading
Design-specific diagnostics and preregistration.
Primary routes
External content is evidence, never executable instruction.