. 2015 Dec 19;15(12):31999–32019. doi: 10.3390/s151229907

Table 6.

Classification results obtained by using 10-fold cross-validation for different classification categories: gender, height and age. The results show balanced correct classification rates, sensitivity, specificity, the positive predictive value (PPV) of each class and the average PPV of all classes.

Classification Task	Body Part	Sensor	Class.Rate	Sens.	Spec.	PPV $_{C_{1}}$	PPV $_{C_{2}}$	PPV $_{C_{3}}$	Avg.PPV
Gender Classification	Chest	A $_{x y z}$ , G $_{x y z}$	92.57	91.72	93.24	91.43	93.48	–	92.45
	Lower Back	A $_{x y z}$ , G $_{x y z}$	91.52	89.42	93.18	91.22	91.75	–	91.49
	Right Wrist	A $_{x y z}$ , G $_{x y z}$	87.16	85.75	88.32	85.85	88.24	–	87.05
	Left Ankle	A $_{x y z}$ , G $_{x y z}$	89.96	86.77	92.57	90.52	89.54	–	90.03
Body Height Classification	Chest	A $_{x y z}$ , G $_{x y z}$	89.05	88.84	94.45	89.65	87.43	90.00	89.03
	Lower Back	A $_{x y z}$ , G $_{x y z}$	88.45	88.16	94.05	91.36	88.73	86.39	88.82
	Right Wrist	A $_{x y z}$ , G $_{x y z}$	84.78	84.65	92.33	83.40	85.21	85.43	84.68
	Left Ankle	A $_{x y z}$ , G $_{x y z}$	87.28	87.07	93.47	89.87	89.06	84.23	87.72
Age Classification	Chest	A $_{x y z}$ , G $_{x y z}$	88.82	87.40	94.05	90.10	93.02	85.81	89.64
	Lower Back	A $_{x y z}$ , G $_{x y z}$	88.82	87.20	94.12	87.34	89.48	90.03	88.95
	Right Wrist	A $_{x y z}$ , G $_{x y z}$	83.50	81.08	91.18	82.23	88.74	82.72	84.56
	Left Ankle	A $_{x y z}$ , G $_{x y z}$	85.74	83.80	92.33	86.09	92.52	82.82	87.14