Difficulty = 1Easy:
 contrast             estimate    SE  df z.ratio p.value
 2reversed - 1quiet      0.027 0.260 Inf  0.104  0.9941 
 2reversed - 3forward    0.169 0.281 Inf  0.603  0.8184 
 1quiet - 3forward       0.142 0.267 Inf  0.533  0.8550 

Difficulty = 2Hard:
 contrast             estimate    SE  df z.ratio p.value
 2reversed - 1quiet     -0.125 0.437 Inf -0.286  0.9559 
 2reversed - 3forward   -1.033 0.442 Inf -2.338  0.0507 
 1quiet - 3forward      -0.908 0.442 Inf -2.056  0.0991 

P value adjustment: tukey method for comparing a family of 3 estimates 
