We derive metal abundance estimates for a large sample of starbursting emission-line galaxies ( ELGs ) .
Our sample is drawn from the KPNO International Spectroscopic Survey ( KISS ) which has discovered over 2000 ELG candidates to date .
Follow-up optical spectra have been obtained for \sim 900 of these objects .
A three step process is used to obtain metal abundances for these galaxies .
We first calculate accurate nebular abundances for 12 galaxies whose spectra cover the full optical region from [ OII ] \lambda \lambda 3726,29 to beyond [ SII ] \lambda \lambda 6717,31 and include detection of [ OIII ] \lambda 4363 .
Using secondary metallicity indicators R _ { 23 } and p _ { 3 } , we calculate metallicities for an additional 59 galaxies with spectra that cover a similar wavelength range but lack [ OIII ] \lambda 4363 .
The results are used to calibrate relations between metallicity and two readily observed emission-line ratios , which allow us to estimate coarse metallicities for 519 galaxies in total .
The uncertainty in these latter abundance estimates is 0.16 dex .
From the large , homogeneously observed sample of star-forming galaxies we identify low metallicity candidates for future study and investigate the metallicity-luminosity relation .
We find a linear metallicity-luminosity relation of the following form : 12 + log ( O/H ) = 4.059 - 0.240 M _ { B } , with an RMS scatter of 0.252 .
This result implies that the slope of the metallicity-luminosity relation is steeper than when dwarf galaxies are considered alone , and may be evidence that the relationship is not linear over the full luminosity range of the sample .