Experimental randomization

The first task considered is the robust estimation of fitting parameters. Following to Peter Huber, the consideration is built at the assumption that the density function of the experimental random errors (8) can be presented in the following form ... 

Another example may be even more interesting one-sided intervals are especially use fill in comparing heavy metal contamination found in an environmental compartment with a legally fixed threshold value. Because of the experimental random error it is not recom-... 

If the original model is sufficiently perfect, the linearization of the problem adequate, the measurements unbiased (no systematic error), and the covariance matrix of the observations, 0y, a true representation of the experimental errors and their correlations, then c2 (Eq. 21c) should be near unity [34], If 0y is indeed an honest assessment of the experimental errors, but a2 is nonetheless (much) larger than unity, model deficiencies are the most frequent source of this discrepancy. Relevant variables probably exist that have not been included in the model, and the experimental precision is hence better than can be utilized by the available model. Model errors have then been treated as if they were experimental random errors, and the results must be interpreted with great caution. In this often unavoidable case, it would clearly be meaningless to make a difference between a measurement with a small experimental error (below the useful limit of precision) and another measurement with an even smaller error (see ref. [41 ). A deliberate modification of the variance-covariance matrix y towards larger and more equal variances might then be indicated, which results in a more equally weighted and less correlated matrix. 

Rees [27] has calculated the effect on the deformation electron density maps of experimental random errors in centrosymmetric crystals ... 

Experimental — Randomized clinical trial — Community trial... 

Values of bcoh,bcoh2 and rinc are listed below (see Table 6.2), for nuclei usually found in polymers. The unity of area is the barn (1 barn = 10 24 cm2). We note that the incoherent scattering cross-section is relatively very large. This is the main origin of the experimental random noise . 

It must be emphasised, however, that potentiometric measurements are thermodynamically comparable only when exactly the same phases are involved in the respective redox reactions. As shovm in Figure V-11 the solubility constant and consequently the Gibbs energy of formation of P-Ni(OH)2 presumably depends on the particle size (compare thick solid and thick dash curves which differ by 0.8 logioAT-units). Thus the total uncertainty in Equation (V.48) is composed of an experimental random error 2cj 1.5 kJ-mol" and a systematic error due to the solid phase used of 4.5 kJ-moT . 

Hennecke, M. (1994). RANEXP Experimental Random Number Generator Package. Computer Physics Communications, 79 261. 

Experimental (random) error Confusing correlation with causation... 

New scaffolds for active ingredients are classically obtained by an experimental random screening. Essential for this high-throughput experiment is a multitude of compounds that has to be purchased, synthesized and handled. For reasons of expense, it is desirable not to test all available compounds, but only those with a high chance of success. One helpful strategy to focus a compound library to a particular target is based on the molecular structure of the protein. 

Evaluation designs. Methods used to select the counterfactual or control group for impact evaluations. They can be broadly classified into three categories experimental (randomized) design, quasi-experimental design, and nonexperimental des n. 

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