Investigators conducted a 9-month randomized, cross-over trial on an inpatient medicine teaching service where 22 faculty provided either: 1) direct supervision where attendings joined work rounds on established (previously admitted) patients or 2) standard supervision where attendings were available, but did not join work rounds. Each faculty member participated in both arms in random order. The primary safety outcome was rate of medical errors. Secondary safety outcomes included deaths and transfers to the intensive care unit. Resident education was evaluated via a time motion study to assess resident participation on rounds and surveys to measure resident and attending educational ratings.