Table 3.

Comparison among different vector representations

		NGram	CEVR	W2V_avg	W2V_idfavg	W2V_maxmin	SEVR
Discontinuation	Sn(%)	59.86	59.97	14.4	19.02	25.47	61.06
	Sp(%)	99.42	99.44	99.93	98.67	99.74	99.43
	AUC	0.796**	0.776*	0.572*	0.588*	0.626*	0.803
Reason	Sn(%)	51.92	51.82	28.25	28.15	36.01	52.35
	Sp(%)	91.24	91.18	83.44	83.29	85.07	91.43
	AUC	0.716***	0.715	0.558*	0.557*	0.605*	0.719

*, ** and *** indicate the statistical significance level of P < .001, P < .05 and P < .1, respectively, for Student’s t test on AUC metric (compared with SVM).