Conceptual Assessment Framework Layer
The conceptual assessment framework layer contains many of the
“tools” of ECD used by test developers such as the student model, the
evidence model, the task model, and the assembly model. Each will
be described below, but the frequent use of the word “model” in ECD
may require explanation. A model is a term used to refer to a
simplified, understandable, usable representation of a far more
complex reality. For example, a road map could be called a “terrain
model.” It is highly useful because it is greatly simplified compared
to reality. It contains the information necessary to travel from one
location to another by car. It is easy to find and use the desired
information because the map does not include the countless details
of the actual terrain that are irrelevant for travel by road. A model
allows focus on the important aspects of a segment of reality for a
particular purpose. A model works to the extent that it captures the
components of reality that are relevant to the purpose for using the
model and omits the irrelevant components.