revealing needed research
theories generalize about phenomena and predict phenomena. they also pinpoint crucial areas to be investigated and crucial problems to be solved. for example, test theory and development have had a long history in education. test developers have made significant contributions to the practice of education. teachers have always used some type test to measure their students' achievement of academic content. the development of tests of academic achievement relies heavily on test theory and validation. an important problem in educational practice today revolves around the results of testing in our schools. for example, it has been well documented that there is an achievement gap between white students and certain groups of ethnic-minority student. this problem might have gone unnoticed if it were not for the documentation provided by state-mandated achievement tests. the no child left behind(NCLB) act was enacted primarily to close the achievement gap. thus, the work of educators at all levels is being shaped by national accountability standards designed to improve the performance of all students on state-mandated tests. consequently, tests seen to be driving educational practice.