Table 1.
Types and characteristics of MAP research from 1911–2019.
| Attributes | Counts/Rates |
|---|---|
| Documents | 3889 |
| Sources | 581 |
| Keywords Plus | 5175 |
| Author’s Keywords | 3110 |
| Average citations/documents | 20.65 |
| Authors | 6662 |
| Author Appearances | 18,666 |
| Authors of single-authored documents | 217 |
| Authors of multi-authored documents | 6445 |
| Single-authored documents | 348 |
| Documents/ Author | 0.584 |
| Authors/Document | 1.71 |
| Co-Authors/Documents | 4.8 |
| Collaboration Index | 1.82 |
| Document types | |
| Article | 3737 |
| Article, book chapter | 38 |
| Article, early access | 3 |
| Article, proceedings paper | 111 |