nal assessment results will be consistent with the more detailed understanding of learning underlying classroom instruction and assessment. As one moves up and down the levels of the system, from the classroom through the school, district, and state, assessments along this vertical dimension should align. As long as the underlying models of learning are consistent, the assessments will complement each other rather than present conflicting goals for learning.
To keep learning at the center of the educational enterprise, assessment information must be strongly linked to curriculum and instruction. Thus another aspect of coherence, emphasized earlier, is that alignment is needed among curriculum, instruction, and assessment so that all three parts of the education system are working toward a common set of learning goals. Ideally, assessment will not simply be aligned with instruction, but integrated seamlessly into instruction so that teachers and students are receiving frequent but unobtrusive feedback about their progress. If assessment, curriculum, and instruction are aligned with common models of learning, it follows that they will be aligned with each other. This can be thought of as alignment along the horizontal dimension of the system.
To achieve both the vertical and horizontal dimensions of coherence or alignment, models of learning are needed that are shared by educators at different levels of the system, from teachers to policy makers. This need might be met through a process that involves gathering together the necessary expertise, not unlike the approach used to develop state and national curriculum standards that define the content to be learned. But current definitions of content must be significantly enhanced based on research from the cognitive sciences. Needed are user-friendly descriptions of how students learn the content, identifying important targets for instruction and assessment (see, e.g., American Association for the Advancement of Science, 2001). Research centers could be charged with convening the appropriate experts to produce a synthesis of the best available scientific understanding of how students learn in particular domains of the curriculum. These models of learning would then guide assessment design at all levels, as well as curriculum and instruction, effecting alignment in the system. Some might argue that what we have described are the goals of current curriculum standards. But while the existing standards emphasize what students should learn, they do not describe how students learn in ways that are maximally useful for guiding instruction and assessment.
In addition to comprehensiveness and coherence, an ideal assessment system would be designed to be continuous. That is, assessments should measure student progress over time, akin more to a videotape record than to