This article describes the use of two linked instruments, the Instructor Effectiveness Check Sheet (IEC) and Instructor Effectiveness Questionnaire (IEQ). The use of an evaluation instrument during a course can enable improvements to be made--even with experienced instructors. Detail can be taken from the IEC and IEQ to find obvious and not so obvious needed changes and attention to individuals in the group. The article gives an example where the instruments were used to teach instructors about different pedagogical constructs, describes further research using the instruments at the Nantahala Outdoor Center, USA, and describes a case study on a wilderness education group that illustrated improvement in effective teaching. (Contains 3 figures, 4 tables, and 2 notes.)