  Using the CTIO 4-m telescope, we have obtained optical spectra of HII regions
in five Sculptor Group dwarf irregular galaxies. We derive oxygen, nitrogen,
and sulfur abundances from the HII region spectra. Oxygen abundances are
derived via three different methods (the ``direct'' method, the empirical
method guided by photoionization modeling of McGaugh (1991), and the purely
empirical method of Pilyugin (2000)) and are compared. Significant systematic
differences are found between the three methods, and we suggest that a
recalibration of the empirical abundance scale is required. The N/O ratio for
the metal-poor dI ESO 473-G24 of log (N/O) = -1.43 +/- 0.03 lies well above the
plateau of log (N/O) = -1.60 +/- 0.02 found by Izotov & Thuan (1999) for a
collection of metal-poor blue compact galaxies. This shows that not all
galaxies with 12 + log (O/H) < 7.6 have identical elemental abundance ratios,
and this implies that the Izotov & Thuan scenario for low metallicity galaxies
is not universal. Measurements of the HII regions in NGC 625 yield log (N/O) =
-1.25. Assuming N production by intermediate mass stars, this relatively high
N/O ratio may be indicative of a long quiescent period prior to the recent
active burst of star formation. The oxygen abundances in the Sculptor Group dIs
are in good agreement with the relationship between metallicity and luminosity
observed in the Local Group dIs. The Sculptor Group dIs, in general, lie closer
to the simple closed box model evolutionary path than the Local Group dIs. The
higher gas contents, lower average star formation rates, and closer resemblance
to closed box evolution could all be indicative of evolution in a relatively
low density environment.
