| for social change | 6 | purpose |
| very | 3 | degree |
| for friction drives | 3 | purpose |
| friction → be → important | 19 |
| friction → be → essential | 6 |
| friction → be → important factor | 3 |
| friction → be of → key importance | 3 |
| negative | neutral | positive |
| 0.183 | 0.640 | 0.177 |
| Raw frequency | 31 |
| Normalized frequency | 0.650 |
| Modifier score | 0.500 |
| Perplexity | 115.149 |