<<<back to statistical tests
Spearman’s rank order correlation coefficient test (Spearman’s rho) is a:
- Test of correlation
- On data in the ordinal format
To find the correct critical value when calculating whether results are statistically significant using Spearman’s rho, you need to know:
- Whether your experimental hypothesis is one-tailed or two-tailed
- Your sample size (n) – e.g. the number of participants in an experiment
- The level of significance (p)
- This will be given to you in the exam
Your results are statistically significant if the observed value is equal to or greater than the critical value.
Note: Tables like the ones below will be provided in the exam – you don’t have to memorise all these critical values!
One-tailed Spearman’s rho
One-tailed: The experimental hypothesis predicts a change in only one direction (also called a directional hypothesis).
The following are critical values of Spearman’s rho for one-tailed experiments where the sample size (n) ranges between 5-20 and for p values of 0.1, 0.05 and 0.01.
n | p = 0.1 | p = 0.05 | p = 0.01 |
5 | 0.8 | 0.9 | 1 |
6 | 0.657 | 0.829 | 0.943 |
7 | 0.571 | 0.714 | 0.893 |
8 | 0.524 | 0.643 | 0.833 |
9 | 0.483 | 0.6 | 0.783 |
10 | 0.455 | 0.564 | 0.745 |
11 | 0.427 | 0.563 | 0.709 |
12 | 0.406 | 0.503 | 0.671 |
13 | 0.385 | 0.484 | 0.648 |
14 | 0.367 | 0.464 | 0.622 |
15 | 0.354 | 0.446 | 0.604 |
16 | 0.341 | 0.429 | 0.582 |
17 | 0.328 | 0.414 | 0.566 |
18 | 0.317 | 0.401 | 0.55 |
19 | 0.309 | 0.391 | 0.535 |
20 | 0.299 | 0.38 | 0.52 |
Your results are statistically significant if the observed value is equal to or greater than the critical value.
Two-tailed Spearman’s rho
Two-tailed: The experimental hypothesis predicts a change in either direction (also called a non-directional hypothesis).
The following are critical values of Spearman’s rho for two-tailed experiments where the sample size (n) ranges between 5-20 and for p values of 0.1, 0.05 and 0.01.
n | p = 0.1 | p = 0.05 | p = 0.01 |
5 | 0.9 | 1 | – |
6 | 0.829 | 0.886 | 1 |
7 | 0.714 | 0.786 | 0.929 |
8 | 0.643 | 0.738 | 0.881 |
9 | 0.6 | 0.7 | 0.833 |
10 | 0.564 | 0.648 | 0.794 |
11 | 0.536 | 0.618 | 0.755 |
12 | 0.503 | 0.587 | 0.727 |
13 | 0.484 | 0.56 | 0.703 |
14 | 0.464 | 0.538 | 0.675 |
15 | 0.446 | 0.521 | 0.654 |
16 | 0.429 | 0.503 | 0.635 |
17 | 0.414 | 0.485 | 0.615 |
18 | 0.401 | 0.472 | 0.6 |
19 | 0.391 | 0.46 | 0.584 |
20 | 0.38 | 0.447 | 0.57 |
Your results are statistically significant if the observed value is equal to or greater than the critical value.