Sample size dependence

The requirements and means of calculating necessary sample size depends on the desired (or practical) comparative sizes of test and control groups. 

The remaining quantities that need to be considered when calculating sample size depend upon the particular statistical test to be used ... 

SD also has a powerful effect upon necessary sample size. This is also approximately a square relationship with sample size depending on the square of the SD. Therefore, if we could halve the variability in our data, the sample size would fall to about a quarter. 

Sample size depends on the acceptable margin of error. For an Attribute MSA, a typical sample size is 30 with a margin of error near 10 percent at 90 percent agreement. 

Note that the sample size depends not only on the value of A, hut also on the individual proportions themselves. The implication of this is that the sponsor must make a reasonable estimate of the response in the placebo group (that is, PpLACEBo) then postulate a value of A that is clinically relevant. The corresponding value of p.pgg.p can be obtained by subtraction. This first sample size estimate ( ) can be improved through the use of a continuity correction, which gives more accurate results when a discrete distribution (in this case the binomial distribution) is used to approximate a continuous distribution (in this case the normal). The sample size formula with continuity correction is ... 

The sample size depends upon expected analyte concentration. Approximately 1-2 g of... 

The interest of the p,SR physicist (or chemist) lies in determining how the muon spin moves due to its coupling to internal fields after the muon has been implanted into the material under study. One directs the beam of polarized muons onto a sample thick and large enough to stop all impinging muons. The proper selection of sample size depends on beam characteristics and will be discussed in sect. 2.5. 

As with any system, the effect of sample size depends on the response characteristics of the detector, but with asphalt this is complicated by the greater association in more concentrated solutions and the dissociation kinetics following injection. There is usually a decrease in the percentage of LMS as lower concentrations are injected. 

The appropriate sample size depends on whether the investigations are carried out in the range of infinite dilution or of finite-concentration . At infinite dilution, the concentrations of the components in the carrier gas may be neglected and thus the gaseous phase may be considered ideal. At finite concentration, a correction for retention calculations should be introduced, which makes them more complicated. Certain limitations of GC methods for physicochemical determinations should also be mentioned. These are mainly restricted to the study of interactions that occur on solids, in liquids, in the mobile gas phase, and at their interfaces. While measurements can be made simultaneously, it is possible that interference from other physicochemical properties of the materials may introduce inaccuracy. Another important limitation is the volatility of the stationary phase in gas-liquid chromatography. 

Nonporous Without network porosity Mostly bound Diffusion through free volumes Very slow, sample-size dependent Various uses from contact lenses to artificial muscles... 

Microporous Various porosity with closed-cell structure (100-1000 A) Mostly bound Combination of molecular diffusion and convection in the water filled pores Slow, sample-size dependent Mainly in biomedical applications and controlled release technology... 

Carbon-sulphur bonds are not hydrolysed by boiling with dilute mineral acids, but are broken by boiling with phosphoric acid of boiling point 215°C [9]. The sample size depends on the use to be made of the hydrocarbon, but typically 1--5 g is used. The hydrocarbon is distilled off and examined as required. Recovery of the hydrocarbon is not quantitative. 

Maximum sample size Depends upon sample tube... 

From the sample-size dependence of chlorine removal, they claim that diffusion of either oxygen or the chlorine containing oxidation products is rate controlling. The diffusion process is retarded by repeated adsorption-desorption from the pore walls, therefore Susa et al. recommend gel-synthesis conditions that result in dried gels containing large pores and small... 

DMA. In DMA a specimen is subjected to an oscillating force and the material s response is recorded as a function of temperature or frequency. Different instrument geometries allow testing of fibres, films, bars or even powders. Optimal choice of testing mode and sample size depends on sample... 

Hancox, R.N., Lamb, G.D., and Lehrle, R.S. (1991) Sample size dependence in pyrolysis an embarrassment or an utility J. Anal Appl. Pyrolysis, 19, 333-347. 

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