Managers praise outstanding work, and criticize awful work. In between "outstanding" and "awful" is a range where most people's work falls. That middle range can be divided into good work (the upper half) and mediocre (the lower half). Typically this mid-range work tends not to be commented upon at all. Managers are too often busy to let everybody know how their work is evaluated.
Ask managers, as I have when consulting, whether they praise people who are doing good work and they reply "No, that's what I pay them for." To which I respond, "So what do you tell the people doing mediocre work?" Often managers claim to indicate their lack of enthusiasm for this ho-hum output. The truth is that much too often both good and mediocre work is left with neither praise nor criticism.
In most organizations it is sufficiently difficult to fire someone that only the truly terrible get fired. Those doing a mediocre job are tolerated because bosses don't have the time to go through all the steps necessary to let them go. Nevertheless, managers need to let the good workers know that they are appreciated, that the difference between their output and that of the also-rans is noted and appreciated.
