Your article on the Teacher Keys evaluation system was accurate, but failed to discuss the critical issue; that is, is it possible to evaluate teaching using any evaluation tool regardless of its sophistication or intricacy? There are at least a few loud voices in the field of education, mine included, which reject the fundamental concept of teacher evaluation through an objective measurement device. I would argue instead that teaching is an art form, not a science, and that art forms are intrinsically not measurable.