Statistics & probability
Paired sample t test
Compare matched observations by analysing their within-pair differences.
A clear answer. Here’s how.
Subtracts each second value from its matching first value, then performs a one-sample t test on those differences. Lists must have equal length, at least two pairs and positive difference variability. Assumes independent pairs and a suitable distribution of differences. Pair order is meaningful; no matching is inferred.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- First sample
- 10, 12, 9, 11, 13
- Second sample
- 8, 9, 11, 7, 10
- Null mean difference (first minus second)
- 0
- Alternative hypothesis
- Different (two-sided)
Example result
- Sample mean difference
- 2
- Observations / pairs
- 5
- t statistic
- 1.90692517849
- Degrees of freedom
- 4
- p-value
- 0.129202984639
A p-value is conditional on the stated null model and sampling assumptions; it is not the probability that the null hypothesis is true.