Hazard warning asks whether the product warns users of a hazard in time and in a way they can act on. A measure relates warnings noticed and acted on to the warnings issued or the hazards present. A warning that is displayed and ignored has not worked. The measure therefore has two parts: delivery and effect. Delivery is countable from the product; effect needs a user study or an incident review. The warning should be tested in the conditions where it matters, including a distracted user and a noisy environment. The measure should also record false warnings, because alarm fatigue degrades every later warning.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.