Taken together, this shortage of ships and qualified mariners is “threaten[ing] our ability to meet national security requirements,” as the outgoing U.S. Transportation Command commander, Gen. Darren McDew, told the Senate Armed Services Committee. Our enemies know that, as capable as our military is, it is a paper tiger if it can’t get to the battlefield on time. The deterrent capability of our military is weakened by our inability to deploy combat-ready forces quickly.
The IRT model underlying ASVAB scoring is the three-parameter logistic (3PL) model. The 3PL model represents the probability that an examinee at a given level of ability will respond correctly to an individual item with given characteristics. Specifically, the item characteristics represented in the 3PL model are difficulty, discrimination (i.e., how well the item discriminates among examinees of differing levels of ability), and guessing (i.e., the likelihood that a very low ability examinee would respond correctly simply by guessing).