2.1. Existing deep surveys
To a large degree, the different selection wavelengths employed in the surveys of Table 1 have been complementary: the B-band will preferentially select the bluer galaxies which are known to contribute most strongly to the evolution of the galaxy population, the I-band is best matched at 0.5 < z < 1.0 to the rest-frame B and V wavebands, allowing the most precise delineation of evolutionary effects with respect to local galaxy samples. The K-band is anchored to that part of the spectrum which shows least evolution. In broad terms there is a large degree of concordance between the results of the above surveys. There are nevertheless some detailed differences which remain to be resolved. One important issue is the location of the bright end of the luminosity function - the CFRS-based LF is significantly brighter than that of the LDSS and allows a greater degree of conventional luminosity evolution in the most luminous galaxies seen today.