| extensively | 13 | degree |
| well | 10 | degree |
| thoroughly | 7 | degree |
| problem → be → studied | 224 |
| problem → be studied in → this work | 3 |
| negative | neutral | positive |
| 0.218 | 0.647 | 0.136 |
| Raw frequency | 227 |
| Normalized frequency | 0.511 |
| Modifier score | 0.750 |
| Perplexity | 348.791 |