Recent observations and theoretical ideas suggest new ways of investigating the inner structure of quasi-stellar objects (QSOs). A spinning, massive black hole seems the most plausible way to explain radio jets (beams) and, through accretion, the enormous luminosities of quasars from radio to beyond X-rays. If the accreting gas has angular momentum it will probably form a disk about the spin of the hole. New evidence for relativistic beaming of the radio emission from quasars' cores supports the idea of a "Unified Scheme" that explains core-dominated quasars as the double, lobe-dominated quasars seen end-on and allows us to use the radio structure to determine an approximate orientation of a quasar to the line-of-sight. Recent observations suggest an axisymmetric structure for the narrow and broad emission line regions (NLR and BLR) and alignment with the radio axis. If this "Unified Scheme" is correct, new observations imply a beamed optical continuum, important in the core-dominated quasars but insignificant in the lobe-dominated quasars. New multi-frequency observations of continuum energy distributions suggest that thermal and other emission from an accretion disk dominates the optical to far ultraviolet spectrum, while hot dust or free-free emission dominates in the near infrared region. The research will test the "Scheme" and explore the consequences of changing inclination for quasars' inner regions by spectro- photometry and polarimetry designed to separate continuum components in the IR-UV, and by observations of emission line spectra and radio, optical and X-ray luminosities in carefully defined quasar samples. These observations can be compared with new kinematic models for the ionization of an axisymmetric broad line region by a disk or "jet" continuum. If the "Scheme" is incorrect, then these observations will test the very strong link between the radio, optical and X-ray properties, and so help define future hypotheses.
