  We propose two statistical tests to investigate how we see the nuclear region
(r < 0.1 pc) of Narrow-Line Seyfert 1 galaxies (NLS1s). 1) The high-ionization
nuclear emission-line region (HINER) test: Seyfert 1 galaxies (S1s) have
systematically higher flux ratios of [Fe VII] lambda 6087 to [O III] lambda
5007 than Seyfert 2 galaxies (S2s). This is interpreted in that a significant
part of the [Fe VII] lambda 6087 emission arises from the inner walls of dusty
tori that cannot be seen in S2s (Murayama & Taniguchi 1998a,b). 2) The
mid-infrared test: S1s have systematically higher flux ratios of the L band
(3.5 micrometer) to the IRAS 25 micrometer band than S2s. This is also
interpreted in that a significant part of the L band emission arises from the
inner walls of dusty tori, because the tori are optically thick enough to
absorb the L band emission if the tori are viewed nearly edge on (Murayama et
al. 2000). Applying these tests to a sample of NLS1s, we have found that the
NLS1s possibly have nearly the same properties as S1s.
