We present some of the strategies being developed to classify and parameterize objects obtained with spectra from the Sloan Digital Sky Survey (SDSS) and the RAdial Velocity Experiment (RAVE) and present some results. We estimate stellar atmospheric
parameters (effective temperature, gravity, and metallicity) from spectral and photometric data and use these to analyse Galactic populations. We demonstrate this through the selection of a sample of candidate Blue Horizontal-Branch and RR Lyrae stars selected from SDSS/SEGUE.
