Hi Tom, I solely agree with you, class preparation is extremely important to help avoid commonly made instructor mistakes. Students can tell very quickly when an instructor is unprepared. Unpreparedness will cause an instrutor to lose credibility. We are all human, and from time to time, we as instructors may make mistakes. Own up to your mistakes and move forward. Students will have greater respect for you, if you take responsibility for your actions. You are right, as adult students, students can see right through things. The old saying still is true, if you mess up "fess" up. Patricia