Flawed content in course text books is another subtle, but serious issue; it can be as serious for some students as the difference between a passing or failing grade, or grade promotion versus retention. Error-free textbook assurance is the responsibility of instructors, students, parents, etc. Whenever errors are discovered in text books they should never be ignored. The publisher should be immediately notified even if an instructor credits a student for correctly answering a question for which an inaccurate answer is provided in a textbook answer key, considering that other instructors and/or assistants may not pick up on the error.