What is simultaneous confidence intervals?

Simultaneous confidence intervals are intervals that are comprised of individual intervals for the separate components of the parameter. A specified confidence level will be suitable for all the confidence intervals. The simultaneous confidence intervals are useful in making multiple comparisons of the treatment means.

What is the Scheffe test used for?

The Scheffé test can be used to determine whether individual means differ, or whether an average one group of means differs from the average of another group of means.

How do you calculate individual confidence level?

Find a confidence level for a data set by taking half of the size of the confidence interval, multiplying it by the square root of the sample size and then dividing by the sample standard deviation.

What is family confidence?

Family confidence coefficient: Indicates the proportion of families of estimates that are entirely correct when repeated samples are selected and the specified CIs for the entire family are calculated for each sample.

Is Tukey or Bonferroni more conservative?

The detailed answer is that the Tukey HSD is a proper “post hoc” test whereas the Bonferroni test is for planned comparisons. The Bonferroni test also tends to be overly conservative, which reduces its statistical power.

What are the confidence intervals for Scheffe’s method?

The resulting confidence intervals are: Tukey 1.13 < µ3-µ1 < 5.31 Scheffé 0.95 < µ3-µ1 < 5.49 which gives Tukey’s method the edge. The normalized contrast, using sums, for the Scheffé method is 4.413, which is close to the maximum contrast.

How is the Scheffe method used in statistics?

In statistics, Scheffé’s method, named after the American statistician Henry Scheffé, is a method for adjusting significance levels in a linear regression analysis to account for multiple comparisons. It is particularly useful in analysis of variance (a special case of regression analysis),…

How many contrasts are there in Scheffe’s method?

If μ1 ., μr are all equal to each other, then all contrasts among them are 0. Otherwise, some contrasts differ from 0. Technically there are infinitely many contrasts. The simultaneous confidence coefficient is exactly 1 − α, whether the factor level sample sizes are equal or unequal.

What is the standard error of Scheffe’s method?

Applying the formulas above we obtain in both cases: and so that the standard error = .5158 (square root of .2661). For a confidence coefficient of 95 percent and degrees of freedom in the numerator of r – 1 = 4 – 1 = 3, and in the denominator of 20 – 4 = 16, we have: