What is a matched pairs t-test example?
A paired t-test is used when we are interested in the difference between two variables for the same subject. Often the two variables are separated by time. For example, in the Dixon and Massey data set we have cholesterol levels in 1952 and cholesterol levels in 1962 for each subject.
How do you know when to use a matched pairs t-test?
You can use the test when your data values are paired measurements. For example, you might have before-and-after measurements for a group of people. Also, the distribution of differences between the paired measurements should be normally distributed.
What is a matched pair design example?
Each pair is matched on gender and age. For example, Pair 1 might be two women, both age 21. Pair 2 might be two men, both age 21. However, unlike the other design, the matched pairs design explicitly controls for two potential lurking variables – age and gender.
Is a paired t-test two tailed?
Like many statistical procedures, the paired sample t-test has two competing hypotheses, the null hypothesis and the alternative hypothesis. The alternative hypothesis can take one of several forms depending on the expected outcome. If the direction of the difference does not matter, a two-tailed hypothesis is used.
How should a paired sample t-test be reported in APA format?
The basic format for reporting the result of a t-test is the same in each case (the color red means you substitute in the appropriate value from your study): t(degress of freedom) = the t statistic, p = p value. It’s the context you provide when reporting the result that tells the reader which type of t-test was used.
What is a two sample t test example?
For the 2-sample t-test, the numerator is again the signal, which is the difference between the means of the two samples. For example, if the mean of group 1 is 10, and the mean of group 2 is 4, the difference is 6. The default null hypothesis for a 2-sample t-test is that the two groups are equal.
What is the key feature of the matched pairs t-test?
A hypothesis test for matched or paired samples (t-test) has these characteristics: Test the differences by subtracting one measurement from the other measurement. Random Variable: ¯¯¯xd x ¯ d = mean of the differences. Distribution: Student’s-t distribution with n – 1 degrees of freedom.