scenario                                                     fixed                  random                    swap                adjusted
                                            reject / mean log-odds  reject / mean log-odds  reject / mean log-odds  reject / mean log-odds
1. equal quality, equal length                     1.000 /   0.286         0.052 /   0.002         0.058 /  -0.000         0.072 /  -0.000
2. equal quality, A longer by 0.5 SD               1.000 /   0.473         0.978 /   0.178         0.998 /   0.180         0.935 /  -0.141
3. A better (mu=0.15), A shorter by 0.5 SD         1.000 /   0.236         0.207 /  -0.053         0.285 /  -0.050         1.000 /   0.289

reference log-odds of 'A preferred' by an unbiased judge (kappa * quality only):
  scenario 1: marginal  -0.002   at equal length  -0.002
  scenario 2: marginal  -0.002   at equal length  -0.145
  scenario 3: marginal   0.138   at equal length   0.283
