The domain modeling layer moves from an investigation of the
relevant real-world domain to a use of selected aspects of the domain
for the purpose of building an assessment argument. The general
form of the assessment argument is “If (X), then (Y) because (Z)”. X
is an observation of test taker behavior or a product of that behavior.
Relevant aspects of the behavior or product form the data on which
the claim is based. Y is a claim that the test taker has or lacks some
KSA or related cluster of KSAs, and Z is the warrant that explains why
the behavior or product demonstrates the possession (or lack of) the
KSA(s). For example, an aspiring firefighter might successfully
complete a task (X) that requires dragging a 200 pound dummy 45
feet through a smoke-filled hallway within a specified time limit.
The ability to complete the task is a partial demonstration that the
test taker has the strength and speed required to be a firefighter (Y),
because the task replicates important physical aspects of the
firefighter’s job under realistic conditions (Z). The parts of the
assessment argument (claims, data, and warrants) are discussed
below.