Assessing understanding might be the most complex task an educator or academic institution is tasked with. Unfortunately, professional development gives a lower level of attention to developing quality assessments, training that is rarely commensurate with this complexity. The challenge of assessment is no less than figuring out what a learner knows, and where he or she needs to go next.
In other words, what does a learner understand? (Terrell Heick at Edutopia)