Nicholas,
Again you are right on target. Feedback should be positive, help the individual student, consistent and timely. Your last statement is particularly true - it's about helping the students improve.
Many times an example up front and definitely a well defined/structured rubric is effective in helping students understand what is expected of them before they begin the assignment/project.
I love the saying: Assessment is not something we do TO students, it's something we do WITH students. Nice job.
