www.mathpages.com/home/kmath210/kmath210.htm outlines the distinction between phase and group velocities, and why the group velocity of electromagnetic waves going faster than the speed of light c does not mean that information is going faster than c, because the phase velocity will always be less than or equal to c. The arguments seem to be clear. However, although the site http://www.physique.usherbrooke.ca/grosdidier/phq210/phasegroup.pdf [Broken] seems to agree with the previous site's mathematical definitions of phase and group velocities, it interprets them differently to say that neither one of them represents the signal velocity, namely the velocity of information transfer. It also defends relativity, but in saying that both phase and group velocities can exceed c, but not the signal velocity. Its arguments are a bit more involved, but also seem clear. However, one of them is not completely correct, since the first one has phase velocity always less than or equal to c, and the second one has phase velocities greater than c. I am missing something here. Please help. Thanks.