Including U.S. territories and ships afloat within territorial waters As of 31 December 2009, a total of 1,137,568 personnel were on active duty within the United States and its territories (including 84,461 afloat). The vast majority (941,629 personnel) were stationed at bases within the contiguous United States. There were an additional 37,245 in Hawaii and 20,450 in Alaska while 84,461 were at sea, 2,972 in Guam and 179 in Puerto Rico.
Soldiers and armies have been prominent in popular culture since the beginnings of recorded history. In addition to the countless images of military leaders in heroic poses from antiquity, they have been an enduring source of inspiration in war literature. Not all of this has been entirely complementary, and the military have been lampooned or ridiculed as often as they have been idolised. The classical Greek writer Aristophanes, devoted an entire comedy, Lysistrata, to a strike organised by military wives, where they withhold sex from their husbands to prevent them from going to war.
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).