Table 1 Results of a paired-samples t-test for Nausea scores based on the system

Paired samples t-test
All condition(N=40)		Matching difference			Degree of Freedom	Significance probability
		Average	Standard Deviation	Standard error of Average		One-side probability	Two-side probability
Matching 1	N_2 – N_1	-1.431	16.246	2.569	39	0.290	0.581
Matching 2	N_3 – N_1	4.770	12.028	1.902	39	0.008	*0.016
Matching 3	N_4 – N_1	8.348	14.032	2.219	39	0.000	*0.001

HMD(N=20)		Matching difference			Degree of Freedom	Significance probability
		Average	Standard Deviation	Standard error of Average		One-side probability	Two-side probability
Matching 1	N_2 – N_1	-5.724	19.673	4.399	19	0.104	0.209
Matching 2	N_3 – N_1	2.862	13.168	2.945	19	0.172	0.343
Matching 3	N_4 – N_1	10.494	17.205	3.847	19	0.007	*0.013

Non-HMD(N=20)		Matching difference			Degree of Freedom	Significance probability
		Average	Standard Deviation	Standard error of Average		One-side probability	Two-side probability
Matching 1	N_2 – N_1	2.862	10.767	2.407	19	0.125	0.249
Matching 2	N_3 – N_1	6.678	10.767	2.407	19	0.006	*0.012
Matching 3	N_4 – N_1	6.201	9.922	2.219	19	0.006	*0.012