Direct replication can be very important, at least in math and the hard sciences.
In physics labs, students conduct experiments that once warranted a Nobel prize. And some of the problem sets that physics grad students work on repeats work that once won a Nobel prize.
When I was in physics grad school, a scandal erupted when Jan Hendrik Schön's "breakthroughs" results on semiconductor nanostructures couldn't be replicated. [1] He'd received a fair bit of acclaim, had one a couple of prizes, and I heard there was even Nobel buzz for him. His papers were in Science, Nature, and Phys. Rev. Letters. Several groups tried and failed over and over to confirm his breakthroughs. It turned out that he had falsified data. 28 of his journal articles were retracted by the publishers and others are still considered suspect.
When a theory or experiment comes along that generates the kind of excitement and interest that can lead to new technology or prestigious grants and awards, replication is important. Science stands on the shoulders of what has come before. We need to know that we're building on a solid foundation.
