Left panel: bias parameter b values as a function of the absolute magnitude limit M_r − 5logh of the sample. Red circles show bias parameter values as found from biased L512 spectra using the filling factor test, b_F, blue boxes indicate bias parameters as found from spectra using the length function test, b_L, and green diamonds show bias parameters using the length function general shape test b_Ls. Right panel: bias function found in this paper compared with bias functions found in other studies. Bias parameter values for SDSS galaxies of various absolute magnitude limits found in this paper are marked by red circles with error bars. Bias parameter values of SDSS galaxies found by Shi et al. (2018) and applying normalising factor b_° = 1.4 are marked by black squares with error bars; that for BOSS galaxies according to Gil-Marín et al. (2017) is shown by a blue diamond, and that for X-ray clusters of galaxies by Schuecker et al. (2001) by a green triangle. Dashed line shows the fit by Norberg et al. (2001), applying bias normalising factor b_° = 1.85. Black, blue, and red lines show fits by Norberg et al. (2001), Tegmark et al. (2004b), and Zehavi et al. (2011), respectively.