Fig. 8. Difference in number of words typed during the recording session: The difference (break - no break) in number of words typed is
presented by protocol group. Standard error of the mean (s/Jn) was 178 for the control group, 69 for the 20 min group, and 90 for the 40 min group, indicating a larger variance in the effect of microbreaks on productivity in the control group.