If IS "is the science of design detection" then ID should be producing lots of testable work on detecting design. It shouldn't even be looking at evolution until is has well-tested and reliable methods of detecting design - and even than that would be expected to be a sideline.
But that hasn't happened. Instead we get lots of books that have more to do with attacking evolution than about methods of detecting design. They produce very little work on detecting design - Dembski is about the only one who has really tried. And even Dembski failed to use his own method correctly when he tried to apply it to the evolution of a bacterial flagellum. Nobody outside the ID movement uses his work at all.
THe term ID was invented because "Creation Science" had been exposed as religion trying to masquerade as science, so creationists needed a new name to hide behind. It is NOT the "science of design detection" because the ID movement doesn't even care about trying to produce such a science. That claim is just one of the lies that the ID movement puts around in their efforts to convince the public that creationism is science.