Thus, we definedgaze velocity averaged over the simulated exercise, usingthe harmonic mean, as:vg¼NfsPN1n¼11rgðnÞrgðn1Þwherefsis the sampling rate of the recording device (in thiscase, 30 Hz),Nis the number of samples recorded duringthe simulated exercise, andrg(n)is the(x,y)position of thegaze (in units of degrees of visual angle) on the samplen.Gaze velocity provides information about how fast the gazeis continuously moving through the exercises, indepen-dently of the spatial configuration of its elements.