| strongly | 7 | degree |
| much | 6 | degree |
| in current literature | 2 | location |
| mechanism → be → debated | 34 |
| mechanism → be → a matter of debate | 12 |
| mechanism → be under → debate | 9 |
| mechanism → be subject to → debate | 3 |
| mechanism → be → the subject of debate | 3 |
| negative | neutral | positive |
| 0.157 | 0.789 | 0.055 |
| Raw frequency | 61 |
| Normalized frequency | 0.525 |
| Modifier score | 0.500 |
| Perplexity | 472.757 |