Table 2. Comparison of five richness estimators based on 1,000 simulation data sets under a random uniform model with S = 1,000 and CV=0.56.

See Table 1 for the notations of the estimators.

Size n (Observed richness)	Estimator	Average estimate	Bias	Sample s.e.	Average estimated s.e.	Sample RMSE	95% CI coverage rate
1,000 (572.3)	${\hat{S}}_{\mathrm{Chao1}}$	858.1	−141.9	44.1	43.2	148.6	0.2
	${\hat{S}}_{\mathrm{Jack1}}$	875.3	−124.7	23.6	24.2	126.9	0
	${\hat{S}}_{\mathrm{CB}}$	905.6	−94.4	67.4	86.9	115.9	0.76
	${\hat{S}}_{\mathrm{LB}}$	936.3	−63.7a	124	116.7	139.2	0.8
	${\hat{S}}_{\mathrm{GP}}$	922.1	−77.9	83.8	80.9	114.4a	0.84a
2,000 (762.7)	${\hat{S}}_{\mathrm{Chao1}}$	903.9	−96.1	25.4	24.2	99.4	0.1
	${\hat{S}}_{\mathrm{Jack1}}$	995.8	−4.2a	20	19.1	20.4a	0.93a
	${\hat{S}}_{\mathrm{CB}}$	916.9	−83.1	25.9	27	87.1	0.17
	${\hat{S}}_{\mathrm{LB}}$	956.7	−43.3	63.8	60.2	77.1	0.77
	${\hat{S}}_{\mathrm{GP}}$	942.3	−57.7	44	43	72.2	0.87
4,000 (886.1)	${\hat{S}}_{\mathrm{Chao1}}$	947.6	−52.4	15.7	14.5	54.7	0.19
	${\hat{S}}_{\mathrm{Jack1}}$	1,011.2	11.2a	14.8	13.5	18.5a	0.86
	${\hat{S}}_{\mathrm{CB}}$	938.4	−61.6	12	11.4	62.8	0
	${\hat{S}}_{\mathrm{LB}}$	977.3	−22.7	38.5	36.3	44.7	0.77
	${\hat{S}}_{\mathrm{GP}}$	970.7	−29.3	25.3	24.3	38.7	0.89a
8,000 (947.9)	${\hat{S}}_{\mathrm{Chao1}}$	975.7	−24.3	10.2	9.6	26.4	0.51
	${\hat{S}}_{\mathrm{Jack1}}$	1,006	6a	9.9	9.2	11.6a	0.88
	${\hat{S}}_{\mathrm{CB}}$	965.3	−34.7	7	6.7	35.4	0
	${\hat{S}}_{\mathrm{LB}}$	993.5	−6.5	28.2	26.4	28.9	0.79
	${\hat{S}}_{\mathrm{GP}}$	987.5	−12.5	15.5	15.5	19.9	0.92a

Notes.

^adenotes the smallest bias, the smallest RMSE, and figure closest to 95% coverage.