Although the literature on effective schools has been replete with information regarding a new paradigm for assessment, some teachers and schools have found it difficult to implement and sustain classroom practices that take them beyond testing discrete knowledge. The reasons for this struggle are as much educational as they are political. Educators tend to teach as they were taught. They tend to allow the textbook to become the curriculum and become somewhat obsessed at covering "stuff" and planning activities rather than "uncovering" the curriculum. Teachers sometimes are willing to accept the illusion of understanding. To begin to address the needs of society and students, administrators must promote a new environment in classrooms. This environment must balance the need to promote and sustain higher levels of thinking and true understanding with the need to meet the requirements of No Child Left Behind (NCLB) and to use traditional testing in a productive manner. Although these goals are challenging and may appear to be diametrically opposed, there is hope. This article discusses enduring concepts of understanding assessment, a framework that will promote and facilitate these two co-existing demands and represent the difference between assessment "of" learning and assessment "for" learning.