Fig. 3

Hand use metrics. Scatter plots comparing the interaction metrics predicted from the algorithm (y-axis) with the actual value from the human observer (x-axis), for each of the three proposed metrics in both hands (left and right hand). (a) Proportion of interaction over total recording time, (b) average duration of interactions (seconds), and (c) number of interactions per hour. The result of a Pearson correlation is shown for (a) and (c) because the data were normally distributed, while (b) was calculated with a Spearman correlation