Comparison of estimators of variance for forest inventories with systematic sampling - results from artificial populations

Forest Ecosystems

Table 3 Paired t-tests under the hypothesis of equal variances. \( \hat{\Delta } \) is the difference between the mean estimate derived with SRS, MAT, SDR, RIP, or DOR and the design based variance (DES). \( \left|\hat{t}\right| \) is the absolute value of the t-statistics (effect size), and \( P\left(\left|\hat{t}\right|\ |\Delta =0\right) \) is the probability of a greater \( \left|\hat{t}\right| \) under the null hypothesis of a zero difference

Estimator contrast	n	\( \hat{\Delta }\times {10}^4 \)	\( \left\|\hat{t}\right\| \)	\( P\left(\left\|\hat{t}\right\|\|\Delta =0\right) \)
SRS-DES	400	0.8	1.31	0.20
	576	0.2	0.37	0.72
	900	0.0	0.16	0.87
	1600	0.0	0.11	0.91
MAT-DES	400	0.2	0.30	0.77
	576	0.3	0.52	0.61
	900	0.3	0.60	0.55
	1600	0.1	0.40	0.69
SDR-DES	400	0.3	0.54	0.60
	576	0.2	0.43	0.67
	900	0.2	0.54	0.59
	1600	0.1	0.40	0.69
RIP-DES	400	0.5	0.73	0.47
	576	0.2	0.34	0.74
	900	0.3	0.68	0.50
	1600	0.2	0.80	0.43
DOR-DES	400	−0.5	0.84	0.41
	576	−0.7	1.39	0.17
	900	−0.5	1.22	0.23
	1600	−0.2	0.73	0.47