Previous abstract Next abstract
We discuss results on the fraction of QSOs with BALs in various subsamples of QSOs. The subsamples are defined by considering radio, IR, optical, UV, and emission-line properties. The fraction of QSOs with BALs is highly dependent on the properties of the subsample. These results have model-dependent implications for the range of sizes of the BAL region covering factors, the large-scale BAL region geometry, and models for anisotropic continuum and line emission in QSOs.