Schade, David Joseph2024-08-152024-08-1519881988https://hdl.handle.net/1828/19626Data from all available complete quasar surveys are combined to form a large sample of objects covering a wide range in redshift and luminosity. Numerical estimates of the luminosity function are derived for redshifts up to ~ 3. The most extreme evolution occurs from the present to redshift ( z) ~ l. ; a maximum in comoving density occurs at z ~ l.7 after which the density declines. Pure density evolution is ruled out. It is shown that a pure luminosity evolution model fits the data for redshift less than that where the density drops as does a second model which is not a pure luminosity evolu­tion model. Beyond this redshift, pure luminosity evolution is not a valid model.59 pagesAvailable to the World Wide WebThesis