The description of the strong AI position in the wikipedia article on the Chinese room describes the blurring of the difference between a simulation and the real thing with respect to the mind:
The definition hinges on the distinction between simulating a mind and actually having a mind. Searle writes that "according to Strong AI, the correct simulation really is a mind. According to Weak AI, the correct simulation is a model of the mind."
If we acknowledge the existence of the real thing, it is often possible to produce an emulation of it. Often, this emulation is better than the real thing for all practical purposes. The purpose of an emulation is to reproduce all relevant features of the external measurable behavior of the real thing. The advantage (and disadvantage) of the notion of emulation is that its intention and meaning is more restricted than the intention and meaning of the notion of simulation.
A simulation related to some real thing can have many different purposes. The perfect reproduction of the external measurable behavior of some real thing is normally not among these purposes. In fact, simulation is often used in situations where there is considerable uncertainty about the actual behavior of the real thing. Simulation is sometimes used to enable observation of internal states which would otherwise be unobservable.
In the context of Searle's Chinese room, we have a computer program related to the understanding of Chinese. The Chinese room is assumed to emulate the operation of this computer program. Now we ask ourself the question whether the Chinese room understands Chinese.
Because the Chinese room emulates the operation of the computer program, the question arises whether the statement that the computer program understands Chinese is equivalent to the statement that the Chinese room understands Chinese.
Is there some sense in which we can claim that the computer program simulates the understanding of Chinese? And I don't mean the claim that it is feigning the understanding of Chinese, because this just uses a different interpretation of the word "simulation" than I would expect here. Or is this really the intended interpretation of the word "simulation" in the quoted passage?