Final answer:
The NOTTUS criterion that fails for "Irreducible complexity" is testability because the concept does not easily lend itself to empirical testing or falsification.
Step-by-step explanation:
The criteria being referenced by the acronym NOTTUS likely pertains to essential features of scientific explanations or hypotheses. The notion of "Irreducible complexity" is a term originating in the context of biological systems, but it has been tied to debates around evolution and intelligent design. Among the NOTTUS criteria (novelty, originality, testability, tractability, utility, and soundness), the failing criteria for the statement on "Irreducible complexity" is testability. This is because a statement that is claimed to be irreducibly complex often does not lend itself to empirical testing or falsification, as it posits that certain biological systems cannot evolve through successive, slight modifications.
As for the provided reference information, it helps establish that scientific hypotheses need to be testable (according to Check Your Understanding question 1a, and as highlighted in Review Questions 9), which aligns with the identification that irreducible complexity fails on the testability criterion.