a faint plate is set such that a total $(S/N)
^{2} >$ 50/1 for all four (red and blue CCDs) on the SDSS spectrographs is achieved. In order to identify and remove cosmic ray hits, each plate must have at least three exposures; the integration time for any single exposure is not longer than 30 minutes. For the purposes of targeting objects on these plates, the boundary between the bright and faint plates is set at $r \sim$ 18.0. The data thus obtained are processed through the SDSS spectroscopic pipeline software (SPECTRO2D and SPECTRO1D), which produces wavelength and flux-calibrated spectra, and also obtains estimates of radial velocities and line indices (Stoughton et al. 2002). Tests of the quality of stellar radial velocities from the SSPP (which uses initial estimates from the SDSS processing pipelines) indicate precisions better than 5 km s$^{-1}$ are achieved for brighter stars, with zero-point offsets of no more than a few km s$^{-1}$, respectively (Paper III). These errors degrade for fainter stars, as expected.

An initial set of candidate member stars of the globular and open clusters studied in the present paper were selected on the basis of photometric and astrometric data (proper motions) from the 