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Yates's correction should always be applied, as it will tend to improve the accuracy of the p-value obtained. [ citation needed ] However, in situations with large sample sizes, using the correction will have little effect on the value of the test statistic, and hence the p-value.
Before the ready availability of statistical software having the ability to evaluate probability distribution functions accurately, continuity corrections played an important role in the practical application of statistical tests in which the test statistic has a discrete distribution: it had a special importance for manual calculations.
However, when (), the Šidák correction for t-test may not achieve the level we want, that is, the true level of the test may not converges to the nominal level as n goes to infinity. This result is related to high-dimensional statistics and is proven by Fan, Hall & Yao (2007) . [ 1 ]
Where there is only 1 degree of freedom, the approximation is not reliable if expected frequencies are below 10. In this case, a better approximation can be obtained by reducing the absolute value of each difference between observed and expected frequencies by 0.5 before squaring; this is called Yates's correction for continuity.
The application of MacCormack method to the above equation proceeds in two steps; a predictor step which is followed by a corrector step. Predictor step: In the predictor step, a "provisional" value of u {\displaystyle u} at time level n + 1 {\displaystyle n+1} (denoted by u i p {\displaystyle u_{i}^{p}} ) is estimated as follows
The Šidák correction is derived by assuming that the individual tests are independent. Let the significance threshold for each test be α 1 {\displaystyle \alpha _{1}} ; then the probability that at least one of the tests is significant under this threshold is (1 - the probability that none of them are significant).
The outer iterations comprise two steps: Solve the momentum equation for a provisional velocity based on the velocity and pressure of the previous outer loop. Plug the new newly obtained velocity into the continuity equation to obtain a correction.
The next, "corrector" step refines the initial approximation by using the predicted value of the function and another method to interpolate that unknown function's value at the same subsequent point. Predictor–corrector methods for solving ODEs