Oversimplification and Overstandardization in Biological Methods: Sperm Bioassays in Ecotoxicology as a Case of Study and a Proposal for Their Reformulation

Table 1

Properties of the parametric estimates obtained by fitting a virtual assay (2,000 repetitions) to models (1) and (7), the first individually applied at 6 increasing times. Negligible experimental error (homoscedastic 𝜎=5×10⁻⁴) and no replicates were supposed. CI (%): average confidence interval (𝛼=0.05) as percentage of the estimate value; STS (%): percentage of statistically significant estimates; SK and KT: skewness and kurtosis coefficients; ALL STS (%): percentage of fittings in which all the estimates were statistically significant; 𝑟²: correlation coefficient between simulated and predicted values. See also Figure 4.

	True parametric values [4]	Overall fitting to the model [4]	Individual fittings to the model [1]
			𝑡1	𝑡2	𝑡3	𝑡4	𝑡5	𝑡6
𝜏	0.600	0.600	—	—	—	—	—	—
CI (%)		0.081	—	—	—	—	—	—
STS (%)		100.0	—	—	—	—	—	—
SK		−0.02	—	—	—	—	—	—
KT		0.07	—	—	—	—	—	—
𝑣	2.500	2.500	—	—	—	—	—	—
CI (%)		0.105	—	—	—	—	—	—
STS (%)		100.0	—	—	—	—	—	—
SK		0.01	—	—	—	—	—	—
KT		−0.04	—	—	—	—	—	—
𝐾	0.800	0.800	0.348	0.742	0.986	1.004	1.002	1.000
CI (%)		0.027	1.60	1.44	1.63	2.05	1.00	0.58
STS (%)		100.0	100.0	100.0	100.0	100.0	100.0	100.0
SK		−0.06	0.07	0.13	−0.07	0.00	−0.05	0.15
KT		0.01	0.16	−0.14	0.05	0.16	0.07	−0.11
𝑚	0.250	0.250	0.463	0.430	0.349	0.252	0.171	0.110
CI (%)		0.100	1.33	1.30	1.71	2.61	1.72	5.80
STS (%)		100.0	100.0	100.0	100.0	100.0	100.0	100.0
SK		0.06	0.03	−0.20	0.08	−0.03	−0.06	−0.02
KT		0.07	0.06	0.04	0.11	0.03	−0.05	0.36
𝑎	2.000	2.000	4.209	3.942	3.559	3.186	2.790	2.641
CI (%)		0.179	6.48	5.50	7.02	10.12	7.38	17.40
STS (%)		100.0	100.0	100.0	100.0	100.0	100.0	100.0
SK		0.13	0.00	−0.14	0.09	−0.03	−0.19	0.73
KT		0.17	0.07	−0.18	−0.02	0.09	0.12	1.98
All STS (%)		100.0	100.0	100.0	100.0	100.0	100.0	100.0
𝑟^2		1.000	1.000	1.000	1.000	0.999	1.000	1.000