several other countries. This feature is also part of the examination system for the International Baccalaureate degree program. In such systems, work is needed to develop procedures for ensuring the comparability of standards across all teachers and schools.
Overall, the purpose is to reflect the variety of the aims of a course, including the range of knowledge and simple understanding explored in A, the practical skills explored in D, and the broader capacities for individual investigation explored in E and F. Validity and comprehensiveness are enhanced, albeit through an expensive and complex assessment process.
There are other possible ways to design comprehensive assessment systems. Portfolios are intended to record “authentic” assessments over a period of time and a range of classroom contexts. A system may assess and give certification in stages, so that the final outcome is an accumulation of results achieved and credited separately over, say, 1 or 2 years of a learning course; results of this type may be built up by combining on-demand externally controlled assessments with work samples drawn from coursework. Such a system may include assessments administered at fixed times or at times of the candidate’s choice using banks of tasks from which tests can be selected to match the candidate’s particular opportunities to learn. Thus designers must always look to the possibility of using the broader approaches discussed here, combining types of tasks and the timing of assessments and of certifications in the optimum way.
Further, in a comprehensive assessment system, the information derived should be technically sound and timely for given decisions. One must be able to trust the accuracy of the information and be assured that the inferences drawn from the results can be substantiated by evidence of various types. The technical quality of assessment is a concern primarily for external, large-scale testing; but if classroom assessment information is to feed into the larger assessment system, the reliability, validity, and fairness of these assessments must be addressed as well. Researchers are just beginning to explore issues of technical quality in the realm of classroom assessment (e.g., Wilson and Sloane, 2000).
For the system to support learning, it must also have a quality the committee refers to as coherence. One dimension of coherence is that the conceptual base or models of student learning underlying the various external and classroom assessments within a system should be compatible. While a large-scale assessment might be based on a model of learning that is coarser than that underlying the assessments used in classrooms, the conceptual base for the large-scale assessment should be a broader version of one that makes sense at the finer-grained level (Mislevy, 1996). In this way, the exter-