He generalized the idea of abstracting current algebra to a different regime, but this was a regime where in the model field theory the current algebra wouldn't actually hold exactly, only for free particles. So basically what he was doing was suggesting that in these limits that he discussed, that the quarks would behave almost like free particles, and that was very interesting because it led to results in agreement with observation. The Stanford and MIT group at SLAC: Dick Taylor, Jerry Friedman, Henry Kendall and many others were doing experiments on deep inelastic scattering; electrons hitting the proton and then going off with a certain momentum transfer, a certain invariant momentum transfer. And what they looked at was what happened… was the probability of that—irrespective of what kind of junk was made on the hadronic side—summing over all the different products that were made on the… out of the proton. They did this in the deep inelastic limit and they had no idea that they were going to be testing the quark idea; they were just interested in what happened in this limit, they thought it would throw some light on physical reality. I don't think they had any notion of testing the quark hypothesis. In fact I think they thought… many people thought that the cross-section would go down, I mean it would be like a standard form factor. But in the long run they found that… in the long run what they accomplished was to confirm the quark hypothesis. What I tell audiences in popular talks is that what they did essentially was to take an electron micrograph of the proton and find that it was made of three nearly punctiform objects with the properties of quarks, including the squares of the charges: four-ninths, one-ninth and one-ninth. Well, Bjorken's idea helped them very much to accomplish this interpretation. But it was somewhat unclear theoretically why one should be able to abstract the result that wasn't even true in the model field theory that we were throwing away, but was true only in the limit of very weak coupling. What was it that made the coupling weak in this deep inelastic limit?