The shortsighted or insecure team leader may feel that the best way to please management is to promise them whatever they ask. But, ultimately, what … - Gerald M. Weinberg

In fact, the average programming manager would prefer that a project be estimated at twelve months and take twelve than that the same project be estimated at six months and take nine. This is an area where some psychological study could be rewarding, but there are indications from other situations that it is not the mean length of estimated time that annoys people but, rather, the standard deviation in the actual time taken. Thus, most people would prefer to wait a fixed ten minutes for the bus each morning than to wait one minute on four days and twenty-six minutes once a week-. Even though the average wait is six minutes in the second case, the derangement caused by one long and unexpected delay more than compensates for this disadvantage.

"Denise: "So your present project is ready to pass to the testing people?" Ralph: "Absolutely." Denise: "Okay, since you're so sure it's adequately tested, I'm going to make you the following generous offer: If fewer than three bugs turn up in your component during testing, I will give you a raise. But if three or more bugs turn up during testing, you won't earn a raise this year." Ralph: "Um . . ." Denise: "Um what?" "Could I just have the component back for a few little tests I want to do?

Overconfidence by the programmer could be attacked by a system that introduced random errors into the program under test. The location and nature of these errors would be recorded inside the system but concealed from the programmer. The rate at which he found and removed these known errors could be used to estimate the rate at which he is removing unknown errors. A similar technique is used routinely by surveillance systems in which an operator is expected to spend eight hours at a stretch looking at a radar screen for very rare events — such as the passing of an unidentified aircraft. Tests of performance showed that it was necessary to introduce some nonzero rate of occurrence of artificial events in order to keep the operator in a satisfactory state of arousal. Moreover, since these events were under control of the system, it was able to estimate the current and overall performance of each operator.