One consistent theme of organizational improvement literature is metrics: measurements of what is important to the organization, e.g., return on investment (ROI). I propose a metric for quality work: retrun on student time (ROST). ROST gets to the heart of the three-pronged challenge of quality work. One prong is whether the work actually helps the student gain knowledge or skills (or both) that he, his parents and his community value. The second prong is effort: can we get enough students to put out sufficient effort, and to persist through difficulties, to complete the work. And, the third prong is coverage: does the work allow students to gain knowledge and skills at a rate that will produce an acceptable quantity of both at graduation?
Of course ROST would have to be considered in tandem with TTR (teacher time required).
I suspect both ROST and TTR are affected by TE (teacher experience), TK (teacher knowledge) and TS (teacher skill) as well as by SI (school infrastructure) and SC (school culture).
Hmmm ... Makes generalized discussions of good schools and bad schools; good curricula and bad curricula; this pedagogy vs. that pedagogy; "constructivist" vs. "instructivist" all look pretty silly, doesn't it? On the other hand, we, meaning everyone interested in educationa, ARE going to talk about public schools because they are our schools. So, maybe it is time we began implementing some metrics that will make that conversation a little more meaningful.