When Joanne Rooney, a principal, asked 17 tenured teachers who were due for their formal supervisory visits at Pleasant Hill School in Palatine, Illinois whether her annual visits and follow-up conferences help them become better teachers," her question was met with muffled laughter. They knew that her rushed, mandatory visits and conferences were, at best, a meager contribution to improving teaching. In this article, Rooney describes a new procedure for teacher supervision which she and her colleagues had developed. Advancing beyond the mechanics of "when," how many" and "how long," they asked more foundational questions. These included: (1) What actions will most help them improve teaching and learning? (2) How can the principal remain accountable--to the public, the profession, and the district--for excellence in teaching, while still trusting the professional expertise of teachers? (3) When should they begin a more aggressive plan of remediation for struggling teachers? (4) What criteria should they use to determine whether new teachers should be given tenure at their school? In addressing these questions, they initiated a program of peer coaching, which not only improved their supervisory system, but advanced them beyond the long-standing tradition of isolated teaching.