Estimates Quotes
There is a great tendency in politics and government operations to get extremely precise numbers because political opponents will always attack all numbers that do not support their positions. The result is that typically, so much time and money goes into trying to get precision, that by the time the numbers are good enough the opportunity to make the right policy decision will have passed. Much information that bears on an issue is never used because it is not precise enough while the precise information is not particularly relevant. See {619763} for a similar related quote.
Also published in What Do You Care What Other People Think, 1988. This was his last publication. He realized that NASA was under so much political and public relations pressure, that important science issues could not be faced squarely. So he wrote his own appendix to the report which was embarrassing to some of the administrators and contractors but was really appreciated by almost all of the scientists and engineers.