| extensively | 10 | degree |
| for treating bone diseases | 2 | purpose |
| melatonin → be → studied | 7 |
| melatonin → be → research | 4 |
| melatonin → be studied for → over decade | 3 |
| melatonin → be studied for → use | 3 |
| negative | neutral | positive |
| 0.053 | 0.580 | 0.367 |
| Raw frequency | 17 |
| Normalized frequency | 0.302 |
| Modifier score | 0.500 |
| Perplexity | 34.583 |