Myth: If employees are not at work when I'm at work, I won't know how hard the employees I supervise are working--or even whether they're working at all. It will be difficult to evaluate performance.

Reality: It is not effective - nor really even possible - to know how hard employees are working by watching them work. Employees who are closely observed often resent it and work less well as a result; it's not possible to stand over someone's shoulder anyway. Unless you are eavesdropping on phone conversations or staring at someone's computer screen, you can't know whether what they are doing is work-related. Thus, eyeball management is not useful, and needs to be replaced with a focus on results--regardless of what arrangement anyone has.