principle will depend on the measurement aperture size, particularly in sources with weak AGN surrounded by vigorous star formation activity. However, the aperture size employed in the H97 optical spectral measurements ($\sim$2$\times$4) are in general some of the smallest available in the literature. In addition, the sensitivity of the observations is considerably higher relative to many other surveys; the optical line ratios from H97 therefore provide the most sensitive optical classifications for weak AGN currently available.

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Observational Details and Data Reduction
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All data presented in this work were obtained using both the short-wavelength (SH, 4.7”$\times$11.3”, $\lambda$ = 9.9-19.6$\mu$m) and long-wavelength(LH, 11.1”$\times$22.3”, $\lambda$ = 18.7-37.2$\mu$m) high-resolution modules of the IRS. These modules have a spectral resolution of R $\sim$ 600. The 32 observations were archived from various programs, including the [*SINGS*]{} Legacy Program (Kennicutt et al. 2003), and therefore contain both spectral mapping and staring observations. In spectral mapping mode, the spacecraft moves in a raster pattern of discrete steps, generally of half-slit width and half-slit length in size, in order to construct a rectangular map of the targeted region. The SH and LH maps for the observations vary in size. In Table 2, we 