Variability in high luminosity active galactic nuclei

The analysis of spectra of 34 quasars observed more than once with IUE is presented. The Lyα+NV and CIV lines in the spectra of some of these objects change in intensity over a time scale comparable to the time scale for changes observed in low luminosity active galactic nuclei. The data clearly suggest that the broad emission line region is considerably smaller than that required to model the emission line spectrum of active galactic nuclei. Also the broad line region does not appear to scale with luminosity as required by the present generation of models of the broad line region. (author)