Flynn wrote a book devoted to the Flynn effect, featuring his theoretical explanation of why the intelligence of worldwide populations has apparently increased from generation to generation. The essence of his theorizing is that because of the societal impact of scientific technology, people of today are much more guided by abstract, rather than…

It is only a slight exaggeration to describe the test theory that dominates educational measurement today as the application of twentieth-century statistics to nineteenth-century psychology. Sophisticated estimation procedures, new techniques for missing-data problems, and theoretical advances into latent-variable modeling have appeared--all…