What is the difference between confidence intervals and hypothesis testing

The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. What is the difference between confidence intervals and hypothesis testing?

Ask Question. Asked 10 years, 1 month ago. Active 2 years, 5 months ago. Viewed 75k times. Explanation with reference and examples would be appreciated. Improve this question. Jeromy Anglim Add a comment. Active Oldest Votes. Which is better?

In addition, the width of the CI can go directly to a discussion of whether this is a strong finding or whether you can only reach a more tentative conclusion If you took a basic statistics class you might initially gravitate toward A.

Improve this answer. John John 21k 9 9 gold badges 47 47 silver badges 83 83 bronze badges. This looks very illuminating to me, so I guess, I need to learn the correct value to look out for!

If not then how? It's very easy to use when you want to test against a hypothetical value other than 0. Show 2 more comments. Michael Hardy 6, 1 1 gold badge 20 20 silver badges 36 36 bronze badges. DavidR DavidR 1, 11 11 silver badges 15 15 bronze badges. The variable of interest is age in years, which is quantitative. The research question includes a specific population parameter to test: 30 years. The appropriate procedure is a hypothesis test for a single mean.

For each research question, identify the variables, the parameter of interest and decide on the the appropriate inferential procedure. Research question: How strong is the correlation between height in inches and weight in pounds in American teenagers? There are two variables of interest: 1 height in inches and 2 weight in pounds. Both are quantitative variables.

The parameter of interest is the correlation between these two variables. We are not given a specific correlation to test. We are being asked to estimate the strength of the correlation. The appropriate procedure here is a confidence interval for a correlation.

Research question: Are the majority of registered voters planning to vote in the next presidential election? The parameter that is being tested here is a single proportion. We have one group: registered voters. This is a specific parameter that we are testing.

The appropriate procedure here is a hypothesis test for a single proportion. We are comparing them in terms of average i. The appropriate procedure here is a hypothesis test for the difference in two means. Research question: On average, how much taller are adult male giraffes compared to adult female giraffes? There are two groups: males and females. The response variable is height, which is quantitative. Minitab Blog. How to Correctly Interpret Confidence Intervals and Confidence Levels A confidence interval is a range of values that is likely to contain an unknown population parameter.

This will be easier to understand after we discuss the graph below. With this in mind, how do you interpret confidence intervals? If the P value is less than your significance alpha level, the hypothesis test is statistically significant. If the confidence interval does not contain the null hypothesis value, the results are statistically significant. If the P value is less than alpha, the confidence interval will not contain the null hypothesis value.

The significance level defines the distance the sample mean must be from the null hypothesis to be considered statistically significant. The confidence level defines the distance for how close the confidence limits are to sample mean. Imagine this discussion between the null hypothesis mean and the sample mean: Null hypothesis mean, hypothesis test representative : Hey buddy! Closing Thoughts In statistical analyses, there tends to be a greater focus on P values and simply detecting a significant effect or difference.

If you like this post, you might want to read the previous posts in this series that use the same graphical framework: Part One: Why We Need to Use Hypothesis Tests Part Two: Significance Levels alpha and P values For more about confidence intervals, read my post where I compare them to tolerance intervals and prediction intervals.

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