variable that are used for assessing levels of student performance and interpreting student work (an example is provided in Table 4–1 for the Evidence and Trade-offs variable). These are augmented with exemplars—samples of actual student work illustrating performance at each score level for all assessment tasks.
The interpretation of these judgments is carried out using progress maps— graphic displays used to record the progress of each student on particular progress variables over the course of the year. The statistical underpinning for these maps is a multidimensional item response model (explained later); the learning underpinning is the set of progress variables. An example of a BEAR progress map is shown in Box 4–2. Teacher and student involvement in the assessment system is motivated and structured through assessment moderation—a process by which groups of teachers and students reach consensus on standards of student performance and discuss the implications of assessment results for subsequent learning and instruction (Roberts, Sloane, and Wilson, 1996).
To summarize, the BEAR assessment system as applied in the IEY curriculum embodies the assessment triangle as follows. The conception of learning consists of the five progress variables mentioned above. Students are helped in improving along these variables by the IEY instructional materials, including the assessments. The observations are the scores teachers assign to student work on the embedded assessment tasks and the link tests. The interpretation model is formally a multidimensional item response model (discussed later in this chapter) that underlies the progress maps; however, its meaning is elaborated through the exemplars and through the teacher’s knowledge about the specific responses a student gave on various items.
Currently, standard measurement models focus on a situation in which the observations are in the form of a number of items with discrete, ordered response categories (such as the categories from an IEY scoring guide illustrated in Table 4–1) and in which the construct is a single continuous variable (such as one of the IEY progress variables described in Box 4–1). For example, a standardized achievement test is typically composed of many (usually dichotomous3) items that are often all linked substantively in some way to a common construct variable, such as mathematics achievement. The construct is thought of as a continuous unobservable (latent) characteristic