What is the expected if the treatment has no effect?
What is expected if the treatment has no effect? -The sample mean should be very different from 80 and should lead you to fail to reject the null hypothesis.
How are the boundaries for the critical region determined?
05, how are the boundaries for the critical region determined? Boundaries are drawn so there is 2.5% (. 025) in each tail of the distribution.
Which combination of factors is most likely to result in a significant outcome for a hypothesis test?
In general, a sample with large variance is more likely to produce a significant result than a sample with small variance.
When choosing a smaller alpha level a researcher risks what?
The smaller the alpha level, the smaller the area where you would reject the null hypothesis. So if you have a tiny area, there's more of a chance that you will NOT reject the null, when in fact you should. This is a Type II error.
What is critical region and level of significance?
The critical region is the region of values that corresponds to the rejection of the null hypothesis at some chosen probability level. The shaded area under the Student's t distribution curve is equal to the level of significance.
What is meant by level of significance and critical region?
The critical region defines how far away our sample statistic must be from the null hypothesis value before we can say it is unusual enough to reject the null hypothesis. Our sample mean (330.6) falls within the critical region, which indicates it is statistically significant at the 0.05 level.Mar 19, 2015
When a research report demonstrates a significant treatment effect?
When a research report demonstrates a significant treatment effect at the . 05 level, you can be more confident that the effect is real than if the researcher had reported a significant effect with an alpha level of only .
What is the effect of decreasing the alpha level for example from α .05 to α 01 )?
Decreasing alpha from 0.05 to 0.01 increases the chance of a Type II error (makes it harder to reject the null hypothesis).
What problem is Cohen's kappa intended to correct?
What problem is Cohen's kappa intended to correct? The simple percentage of agreement tends to overestimate the true level of agreement between two observers.
Can you have statistical significance and not practical significance?
If the study is based on a very large sample size, relationships found to be statistically significant may not have much practical significance. Almost any null hypothesis can be rejected if the sample size is large enough.
What is Alpha in statistical significance?
Alpha is a threshold value used to judge whether a test statistic is statistically significant. It is chosen by the researcher. Alpha represents an acceptable probability of a Type I error in a statistical test. Because alpha corresponds to a probability, it can range from 0 to 1.Jan 1, 2011
How does significance level affect type 1 error?
That's because the significance level (the Type I error rate) affects statistical power, which is inversely related to the Type II error rate. This means there's an important tradeoff between Type I and Type II errors: Setting a lower significance level decreases a Type I error risk, but increases a Type II error risk.Jan 18, 2021