Statistical test of significance

There are a large number of statistical distributions which have for the most part been derived from the normal frequency distribution. The principles underlying only three of these distributions will be presented here. These distributions form the basis for the most frequently used statistical tests of significance. 

Implementation by Use of the Z and Chi-Square (yf) Tests Charts for mean, range, and standard deviation are seldom found in clinical laboratories because of the time required for calculating the control statistics. These control procedures are probably practical only when computerized data handhng is available. An easy way of implementing these procedures on computers is to employ statistical tests of significance. A Z-test can be used to determine whether the mean has changed from its original value, and a can... 

The choice of the optimal values of the parameter k we can do by means of statistical test of significance for regression coefficients in terms of Student s t-test. 

This test is similar to the statistical tests of significance described earlier. In this case, the test of significance is being performed on S2/x. Instead of 0.05, some other level of significance could be used if desired. 

Alternatively, stability can be assessed over at least three intervals (including the initial analysis as one interval) to determine if any instability trends are present. Determination of the statistical significance of any differences in concentration observed at the different time intervals can in the first instance use standard statistical tests for differences between means and variances (Section 8.2.5). It is more difficult to determine whether or not any such differences represent a trend. In principle the analyst could determine the slope of the plot of measured concentration vs time and apply statistical tests to the variance of the slope to determine whether the slope differs significantly from zero (Section 8.3) three points on such a plot are the bare minimum to establish a slope, and in any event for any statistical test of significance, appropriate confidence limits and confidence levels must first be decided on. Thus, while... 

With the use of desktop computers and work stations now common, it is possible for corrosion researchers to put in their data and come out with analysis of variance tables for factorial experiments and multiple linetir regression analysis tables for uncontrolled experiments. Most such tables include a statistical test of significance for observed effects. That test (such as a F test) is a measure of the probability that an observed effect either exists or is caused by random error. 

The main advance that Jacobs made was to use larger sample sizes (than the few plants characteristic of many earlier studies by developmental anatomists), to show reproducibility, and to analyze results with statistical tests of significance. Because he used whole-mount clearing methods (rather than serial sections of paraffin-embedded tissue), it was feasible to process the large samples. The stained tracheary cells could be seen through the cleared outer tissue (Fig. 4.1). 

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