Contents
What is meant by the critical region?
A critical region, also known as the rejection region, is a set of values for the test statistic for which the null hypothesis is rejected. i.e. if the observed test statistic is in the critical region then we reject the null hypothesis and accept the alternative hypothesis.
What is meant by level of significance?
The significance level is the probability of rejecting the null hypothesis when it is true. For example, a significance level of 0.05 indicates a 5% risk of concluding that a difference exists when there is no actual difference.
What is the use of level of significance in determining the rejection or critical region?
The significance level is a threshold we set before collecting data in order to determine whether or not we should reject the null hypothesis. We set this value beforehand to avoid biasing ourselves by viewing our results and then determining what criteria we should use.
How do you create a critical region?
➢ To determine the critical region for a normal distribution, we use the table for the standard normal distribution. If the level of significance is α = 0.10, then for a one tailed test the critical region is below z = -1.28 or above z = 1.28.
What is meant by the noncritical region?
The noncritical region is the range of values of the test statistic that indicates that the difference was probably due to chance and the null hypothesis should not be rejected.
What does p-value 0.05 mean?
P > 0.05 is the probability that the null hypothesis is true. A statistically significant test result (P ≤ 0.05) means that the test hypothesis is false or should be rejected. A P value greater than 0.05 means that no effect was observed.
How do you state a rejection region?
Rejection Regions and Alpha Levels You, as a researcher, choose the alpha level you are willing to accept. For example, if you wanted to be 95% confident that your results are significant, you would choose a 5% alpha level (100% – 95%). That 5% level is the rejection region.
What is the significance of a critical region?
Critical Regions. This relationship can be in the form of scores being similar, like a correlation, or different, like a t -test. When testing for significance, you are testing your data to see if your value falls in the critical region, defined as the statistical value that will allow you to reject the null hypothesis.
Is the significance level and critical value the same thing?
1 Answer 1. They are not the same concept. They are, however, related. For a simple null hypothesis, your significance level is the type I error rate that you choose, which is the long-run proportion of times you would reject the null hypothesis when the null hypothesis was true (and the other assumptions all held true).
What is the critical value of a statistic?
The critical value is the value of the test statistic that marks the boundary of your rejection region. The actual type I error rate you get* with using that critical value will be your significance level.
Is the rejection region equal to the critical value?
The critical value so obtained also appears on the left side. (Since it is on the left side, this critical value is negative.) The shaded region or the critical region is equal to the significance level (α). The next figure again shows the rejection region for the one-tailed test and how the critical value appears on it: