  Of course, this view about experiments is not uncontested. It is true that, quite often, experimentalists infer something about a system distinct from the system they interfere with. However, it is not clear whether this inference is proper part of the original experiment. Peschard (2010) mounts a criticism along these lines, and hence can be seen as a defender of Gilbert and Troitzsch. Peschard argues that the fundamental assumption of their critics—that in experimentation, just as in simulation, what is manipulated is a system standing in for a target system—is confused. It confuses, Peschard argues, the epistemic target of an experiment with its epistemic motivation. She argues that while the epistemic motivation for doing experiments on C. elegans might be quite far-reaching, the proper epistemic target for any such experiment is the worm itself.  In a simulation, according to Peschard, however, the epistemic target is never the digital computer itself. Thus, simulation is distinct from experiment, according to her, in that its epistemic target (as opposed to merely its epistemic motivation) is distinct from the object being manipulated. Roush (2017) can also be seen as a defender of the Gilbert and Troitzsch line, but Roush appeals to sameness of natural kinds as the crucial feature that separates experiments and simulations. Other opponents of the identity thesis include Giere (2009) and Beisbart and Norton (2012, Other Internet Resources).