Table 2.

Summary statistics for various parameters in selected lognormal models from Table 1, as extracted from QRAD. Model numbers and parameters correspond to those described in the text. Reported means and variances are based on QRAD estimates after logarithmic transformation.

Model (no.)	parameter	mean, μ	variance, σ2	expected value*	percentiles:	12.5%	87.5%
Quantal-linear (1)	β1	−0.470	1.688	1.453		0.130	2.902
Multi-stage (2)	β1	−1.006	4.949	4.341		0.0	2.052
	β2	−1.016	5.013	4.440		0.0	1.303
Weibull (3)	α	−0.243†	2.467†	2.693†		0.370	2.594
	β	−0.464	1.535	1.355		0.130	2.659
Gamma (4)	α	−0.153†	2.637†	3.206†		0.315	3.510
	β	−0.587	5.659	9.414		0.039	5.854
Logistic (5)	β1	1.018	0.603	3.744		1.100	6.620
Log-Logistic (6)	β1	0.274	0.960	2.125		0.448	3.777
Probit (7)	β1	0.473	0.638	2.206		0.589	3.687
Log-Probit (8)	β1	−0.186	0.579	1.108		0.311	1.948

^*For Y ~ LN(μ,σ²), E[Y] = exp{μ + σ²}.

^†Values for α component in Models (3) and (4) are based on log(α′) = log(α – 0.2).