Table 3.

Linear regression analysis between usability and biometric variables.

		Unstandardized coefficients			P valuea
		β	SE
SUS-10b × positivity
	Text (n=19)	1.82	1.02	.09
	Voice (n=24)	1.313	1.361	.35
SUS-10 × average δ wave activity
	Text (n=17)	0.153	0.08	.07
	Voice (n=23)	0.062	0.12	.61
SUS-10 × average θ wave activity
	Text (n=17)	0.212	0.1	.05
	Voice (n=23)	0.083	0.146	.57
SUS-10 × average α wave activity
	Text (n=17)	0.196	0.083	.03
	Voice (n=23)	0.054	0.124	.67
SUS-10 × average β wave activity
	Text (n=17)	0.251	0.143	.10
	Voice (n=23)	0.03	0.152	.85
SUS-10 × average γ wave activity
	Text (n=17)	0.148	0.177	.42
	Voice (n=23)	–0.017	0.146	.91
SUS-10 × SUISQ-MRc (n=24)		8.100	2.976	.01

^aPearson χ² test.

^bSUS-10: System Usability Scale.

^cSUISQ-MR: Standardized Questionnaires for Voice Interaction Design Short Version.