Using the CDF detector, dijet and W production with rapidity gaps
has been searched for as evidence for hard-pomeron induced diffraction.
Diffractive W's are sensitive to a pomeron with a hard-quark structure,
while diffractive dijets are sensitive to both hard-gluon and hard-quark
structure.  No evidence of diffractive W's has been found down to the few
percent level and the fraction of diffractive dijets is measured to be
(-0.30 =/- 0.37%,