Significance at 5% Level

Thread starter kma27
Start date Aug 4, 2008
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Significance

In summary, the significance at 5% level is a statistical test where the null hypothesis is rejected if the p-value is less than 0.05. This is a widely accepted convention in the scientific community, balancing between being too strict and too lenient. The significance level is determined before the study and can be adjusted. It differs from the p-value, which is the probability of obtaining the observed results if the null hypothesis is true. A p-value less than 0.05 does not always indicate statistical significance, as other factors should also be considered.

Aug 4, 2008

kma27

Determine whether a correlation coefficient of r = –0.405 is significant at the 5% level for a sample size of 22.

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Aug 4, 2008

Focus

Work out the observed correlation coefficiency, then construct a confidence interval for the coefficient http://www2.sas.com/proceedings/sugi31/170-31.pdf might help.

Good luck

1. What does "Significance at 5% Level" mean?

The significance at 5% level refers to a commonly used statistical test where the null hypothesis is rejected if the calculated p-value is less than 0.05. This means that there is a 5% chance of falsely rejecting the null hypothesis when it is actually true.

2. Why is 5% used as the significance level?

The 5% significance level is a convention that has been widely accepted in the scientific community. It strikes a balance between being too strict and potentially missing important findings, and being too lenient and potentially accepting false results.

3. How is the significance level determined?

The significance level is determined before the start of the study and is usually set at 5% or 0.05. However, it can be adjusted based on the type of study and the level of certainty desired by the researcher.

4. What is the difference between significance level and p-value?

The significance level is a fixed threshold that is set before the study begins, while the p-value is the probability of obtaining the observed results if the null hypothesis is true. If the p-value is less than the significance level, the results are deemed statistically significant.

5. Is a result with a p-value less than 0.05 always considered statistically significant?

No, a result with a p-value less than 0.05 does not always indicate statistical significance. Other factors such as sample size, effect size, and study design should also be taken into consideration when determining the significance of a result.