← Back to Statistics
T-Tests
Paired Samples T-Test
Compare paired or before-after continuous measurements.
Calculation engine
Client-side JavaScript; no external statistics package is loaded.
Results are calculated in the browser and are not uploaded.
Client-side JavaScript; no external statistics package is loaded.
Results are calculated in the browser and are not uploaded.
Method overview
When to use
Use when the same subjects are measured twice, or when observations are naturally matched.
Input requirements
Enter two numeric vectors with the same number of values. The first value in group 1 is paired with the first value in group 2.
Key assumptions
- Pairs are correctly matched.
- Differences between paired values are approximately normally distributed.
- The paired differences are independent across subjects.
Null hypothesis
H₀: the mean paired difference equals 0.
Method used
One-sample t-test applied to paired differences; P value from the t distribution.
References
- Altman DG. Practical Statistics for Medical Research. Chapman & Hall, 1991.
Data input and results
For paired data, raw mode requires two columns in the same order. Summary mode requires n, mean paired difference and SD of paired differences.
No calculation has been performed.