Matched-Pair t-Test Task

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A Matched-Pair t-Test Task is a statistical hypothesis testing task used to describe an matched-pair t-test.



References

2017a

[math]\displaystyle{ t = \frac{\overline{X}_D - \mu_0}{\frac{s_D}{\sqrt{n}}}. }[/math]
For this equation, the differences between all pairs must be calculated. The pairs are either one person's pre-test and post-test scores or between pairs of persons matched into meaningful groups (for instance drawn from the same family or age group: see table). The average (XD) and standard deviation (sD) of those differences are used in the equation. The constant μ0 is non-zero if you want to test whether the average of the difference is significantly different from μ0. The degree of freedom used is n − 1, where n represents the number of pairs.

2017b

*The sampling method for each sample is simple random sampling.
*The test is conducted on paired data. (As a result, the data sets are not independent.)
*The sampling distribution is approximately normal, which is generally true if any of the following conditions apply.
* The population distribution is normal.
* The population data are symmetric, unimodal, without outliers, and the sample size is 15 or less.
* The population data are slightly skewed, unimodal, without outliers, and the sample size is 16 to 40.
* The sample size is greater than 40, without outliers.

2017c

  • (SPSS, 2017) ⇒ http://libguides.library.kent.edu/SPSS/PairedSamplestTest
  • The Paired Samples t Test compares two means that are from the same individual, object, or related units. The two means typically represent two different times (e.g., pre-test and post-test with an intervention between the two time points) or two different but related conditions or units (e.g., left and right ears, twins). The purpose of the test is to determine whether there is statistical evidence that the mean difference between paired observations on a particular outcome is significantly different from zero. The Paired Samples t Test is a parametric test.
This test is also known as:
* Dependent t Test
* Paired t Test
* Repeated Measures t Test
*The variable used in this test is known as:
Dependent variable, or test variable (continuous), measured at two different times or for two related conditions or units
(...) Note: The Paired Samples t Test can only compare the means for two (and only two) related (paired) units on a continuous outcome that is normally distributed. The Paired Samples t Test is not appropriate for analyses involving the following: 1) unpaired data; 2) comparisons between more than two units/groups; 3) a continuous outcome that is not normally distributed; and 4) an ordinal/ranked outcome.