A cognitive psychologist investigated the impact of office lighting designs on task concentration. They used an independent measures design to compare concentration ratings (from 0 to 18, where 0 = 'lowest concentration' and 18 = 'highest concentration') given to employees working under warm light compared to those working under cool blue light. Some of the data collected is presented in the table below.
| Concentration ratings (0 to 18) under warm light compared to cool blue light | Cool blue light | ||
|---|---|---|---|
| Warm light | Cool blue light | ||
| Rating | Rank | Rating | Rank |
| 15 | 17 | 10 | 11 |
| 12 | 13.5 | 3 | 1 |
| 8 | 8 | 5 | 4 |
| 14 | 16 | 4 | 2.5 |
| 13 | 15 | 7 | 6.5 |
| 16 | 18 | 12 | 13.5 |
| 4 | 2.5 | 6 | 5 |
| 9 | 9.5 | 11 | 12 |
| 17 | 19 | 9 | 9.5 |
| 18 | 20 | 7 | 6.5 |
Explain what ranking the data means in the context of this study.
