"Many of the questions and tasks we are developing in the York Science project can be described as 'diagnostic'. That is, not only do they tell you which students have some understanding of the idea you are interested in, they also give you some information about the misconceptions of those who do not use the accepted scientific explanation."
Classroom Assessment: Minute by Minute, Day by
Day
In classrooms that use assessment to support learning, teachers continually adapt
instruction to meet student needs.
"A diagnostic question (or task) is one which provides evidence of a learner's understanding of a specific idea. The pupil's response gives us reasonably clear evidence about whether he or she understands, or does not understand, this idea. Sometimes the question can also help us to diagnose what a pupil's difficulty is - why he or she is not giving the correct answer. If so, this may make it easier to respond effectively and help pupils move their understanding on."