There is often no simple or single way to interpret assessment results or to make instructional decisions based on results. Thus, This research found that classroom-based evaluation calls for a great deal of judgment, which can be enhanced if the logic of evaluation is understood. This consists of comparisons between observed or actual states of affairs and desired states of affaire. When there is a mismatch, change is call for that will reduce the mismatch. The key is that how to deal with the difference between personal and professional decision-making. The latter one must be systematic, explicit, and well documented.