A quote from Surely You’re Joking, Mr. Feynman! (February 1, 2011)

The real trouble was that no one had ever told these fellows anything. The army had selected them from all over the country for a thing called Special Engineer Detachment — clever boys from high school who had engineering ability. They sent them up to Los Alamos [to work on the nuclear bomb project]. They put them in barracks. And they would tell them nothing.

Then they came to work, and what they had to do was work on IBM machines — punching holes, numbers that they didn’t understand. Nobody told them what it was. The thing was going very slowly. I said that the first thing there has to be is that these technical guys know what we’re doing. Oppenheimer went and talked to the security and got special permission so I could give a nice lecture about what we were doing, and they were all excited: “We’re fighting a war! We see what it is!” They knew what the numbers meant. If the pressure came out higher, that meant there was more energy released, and so on and so on. They knew what they were doing.

Complete transformation! They began to invent ways of doing it better. They improved the scheme. They worked at night. They didn’t need supervising in the night; they didn’t need anything. They understood everything; they invented several of the programs that we used.

So my boys really came through, and all that had to be done was to tell them what it was. As a result, although it took them nine months to do three problems before, we did nine problems in three months, which is nearly ten times as fast.