When the AAVSO was founded,
variables seemed to be a rare class of stars, and intrinsic variables with very
small amplitudes were practically unknonw. Now, thanks to photoelectric
photometry, 44% of the known variables among the naked eye stars are variable
by less than 0.1 magnitude and only 22% by over 0.5 magnitude. Thus the most
common types known in 1911 now constitude an elite minority.