 Given a target system to be modeled, and invoking the faithful model assumption, there are two basic approaches to model confirmation discussed in the philosophical literature on modeling following a strategy known as piecemeal improvement (I will ignore bootstrapping approaches as they suffer similar problems, but only complicate the discussion). These piecemeal strategies are also found in the work of scientists modeling actual-world systems and represent competing approaches vying for government funding (for an early discussion, see Thompson 1957). 