The error values for <i>e</i>_<i>c</i> and <i>e</i>_<i>r</i> by volunteer with the mean optimal settings, i.e. volunteer-independent settings (see Eq (16)).

The error values for ec and er by volunteer with the mean optimal settings, i.e. volunteer-independent settings (see Eq (16)).采用平均最优设置（即与志愿者无关的设置，详见式(16)）时，各志愿者对应的ec与er误差值。