Influence of distance metric
Minkowski-distance-based
The variation of the distance metric showed almost no effect in the case of the four gestures (rs, pw, fl, ex); see Fig. The observed behaviour in the case of data which included the pointing gesture exposed the following differences (Fig. Distance metric influence on cross-validation accuracy, gestures (rs, pw, pn, fl, ex), Including the wrist rotation gestures without pointing (weighting factor of When additional including the pointing gesture again, the effect was comparable, although pointing influenced the Minkowski-norm-based distances slightly more. For the Mahalanobis distance, the accuracy dropped from 97% until it reached a stabilization level of about 88%. The Minkowski-based norms started at 100% accuracy for low numbers of Figure The evaluation of the distance metrics showed that differences are not evident in all cases. It can be summarized that the Mahalanobis distance is not recommended to be used for the present data. Due to the necessary calculation of the covariance matrix and its inverse, it is also of disadvantage with respect to computational resources.The Minkowski-distance-based metrics differ regarding the chosen order of norm, especially for high numbers of 