models, explaining how these stories have grown and adapted to handle the increasingly complex demands of assessment. Knowing the history of these adaptations may help in dealing with new demands from more complex models of learning and the types of stories we would now like to be able to tell in many educational contexts.
An example of the relationships among the conception of learning, the observations, and the interpretation model is provided by the Berkeley Evaluation and Assessment Research (BEAR) Center (Wilson and Sloane, 2000). The BEAR assessment system was designed to correspond to a middle school science curriculum called Issues, Evidence and You (IEY) (Science Education for Public Understanding Program, 1995). We use this assessment as a running example to illustrate various points throughout this chapter.
The conception of cognition and learning underlying IEY is not based on a specific theory from cognitive research; rather it is based on pedagogic content knowledge, that is, teachers’ knowledge of how students learn specific types of content. Nevertheless, the BEAR example illustrates many of the principles that the committee is setting forth, including the need to pay attention to all three vertices of the assessment triangle and how they fit together.
The IEY curriculum developers have conceptualized the learner as progressing along five progress variables that organize what students are to learn into five topic areas and a progression of concepts and skills (see Box 4–1). The BEAR assessment system is based on the same set of progress variables. A progress variable focuses on progression or growth. Learning is conceptualized not simply as a matter of acquiring more knowledge and skills, but as progressing toward higher levels of competence as new knowledge is linked to existing knowledge, and deeper understandings are developed from and take the place of earlier understandings. The concepts of ordered levels of understanding and direction are fundamental: in any given area, it is assumed that learning can be described and mapped as progress in the direction of qualitatively richer knowledge, higher-order skills, and deeper understandings. Progress variables are derived in part from professional opinion about what constitutes higher and lower levels of performance or competence, but are also informed by empirical research on how students respond or perform in practice. They provide qualitatively interpreted frames of reference for particular areas of learning and permit students’ levels of achievement to be interpreted in terms of the kinds of knowledge, skills, and understandings typically associated with those levels. They also allow individual and group achievements to be interpreted with respect to the achievements of other learners. The order of the activities intended to take