Undergarment Boudreaux showed the world that an American woman could establish and run a company, and she also caused a revolution in the underwear industry. In 1913, a New York socialite named Mary Phelps Jacob created the first modern brassiere by tying two handkerchiefs together with ribbon. Jacob's original intention was to cover the whalebone sticking out of her corset, which was visible through her sheer dress. Jacob began making brassieres for her family and friends, and news of the garment soon spread by word of mouth. By 1914, Jacob had a patent for her design and was marketing it throughout
Item response theory Item response theory In psychometrics, item response theory (IRT) (also known as latent trait theory, strong true score theory, or modern mental test theory) is a paradigm for the design, analysis, and scoring of tests, questionnaires, and similar instruments measuring abilities, attitudes, or other variables. It is a theory of testing based on the relationship between individuals' performances on a test item and the test takers' levels of performance on an overall measure of the ability that item was designed to measure. Several different statistical models are used to represent both item and test taker characteristics. Unlike simpler alternatives for