Though AU has a specific policy regarding professor attendance (including notification of department heads and finding substitutes or assigning make-up work), it is not well-publicized and a small amount of professors seem to be taking advantage of this.
Undoubtedly, most professor absences are caused by unforseen circumstances like illness or family crises. When this happens, most professors go out of their way to provide flexible make-up options to their students, which is much appreciated.
But some professors go a bit too far, including a professor who once had a baby mid-semester and had students come to make-up classes on Saturdays at the end of the semester, or else miss out on core class material altogether. Clearly, it was poor planning all around; personal issues are understandable, but should not conflict with students getting the education they're paying top-dollar to get. And though most adjuncts are fantastic (particularly in applied fields of study), some seem unable to appropriately balance the demands of teaching with the time commitments required by their jobs.
Cancelling classes is not only rude and inconvenient to students, but costly as well. Every class session of a regular twice-a-week class costs students around $100.
Professors: We respect you, but if you're going to make the commitment to teach, then teach. Especially when you grade students down for not showing up.
