My dissertation introduces a new account of how empirical methods and lines of evidence can come to bear on cosmological model-building. Through a careful study of the recent history of cosmology and dark matter research, I explicate a new type of justification for experiments, a `method-driven logic'. This structure of justification underlies terrestrial experiments researching dark matter and dark energy, but it is more generally prevalent in cases of an underdescribed target. Using a method-driven logic comes with a cost, however. Specifically, interpreting the empirical results of experiments justified through a method-driven logic is non-trivial: negative results warrant secure constraints on the space of possibilities for the target, whereas significant positive results remain ambivalent. While this ambivalence
can be resolved through the amalgamation of multiple lines of evidence, this solution is sometimes faced with conflicts between those lines of evidence. I propose that, under specific circumstances, restricting the relevant empirical evidence can be warranted. Finally, I discuss the use of cosmological evidence as a constraint in other subfields of physics. This brings me full-circle on the integration of disciplines in cosmology|an integration driven by experimental practice
