1 Sample |
One sample t test
If sigma is unknown, use a one sample t test to determine if the sample is likely to have come from a given population with a defined mean. |
Example |
Excel |
SPSS |
R |
2 Samples
Paired
(or dependent, repeated measures) |
Paired t test
The paired-samples t test is used when the data is from related, paired or longitudinal samples. |
Example |
Excel |
SPSS |
R |
2 Samples
Unpaired
(or independent) |
Unpaired t test.
An unpaired t test is used to assess if the mean values of two independent samples are equal. Firstly, you need to assess equality of variances using an F-test, details of which are given within the examples below. |
Example |
Excel (σ_{1}=σ_{2})
Excel (σ_{1}≠σ_{2}) |
SPSS |
R |
3+ Samples
Related (or dependent) |
One-way repeated measures (within groups) ANOVA
One-way repeated measures analysis of variance (ANOVA) is a method for detecting differences between related mean values, it is an extension of the paired t test. A post-hoc test is needed to investigate where these differences might occur. |
Example |
Excel |
SPSS |
R |
3+ Samples
Unrelated (or independent) |
One-way (between groups) ANOVA
One-way analysis of variance (ANOVA) is a method for testing whether three or more populations have the same mean value and is an extension of the unpaired t test. A post-hoc test is needed to investigate where these differences might occur. |
Example |
Excel |
SPSS |
R |
3+ Samples
Unrelated (or independent) |
Two-way (between-groups) ANOVA
Two-way (or three-way analysis of variance) is used to explore if two or more factors can influence the dependent variable. |
Example |
Excel |
SPSS |
R |
Relationship |
Pearson's Correlation
Pearson’s Product-Moment Correlation (r) is used to measure the strength and direction of the association between two variables. The value of Pearson’s r is between +1 and –1: where r = +1 is a perfect positive correlation, r = -1 a perfect negative correlation and r=0 indicates no correlation between the variables. |
Example |
Excel |
SPSS |
R |