Table 1.
Weighting of each criterion in the ranking formulae A and B.
| Criterion | Weighting for formula A | Weighting for formula B |
| Title | 10 | 10 |
| Subtitle | 10 | 10 |
| Author keywords | 5 | 5 |
| Major MeSHa termsb | 4 | 4 |
| Minor MeSH terms | 1 | 1 |
| Nonexploded indexing | 3 | 3 |
| Exploded indexingc | 1 | 1 |
| Manual indexingd | 3 | 3 |
| Automatic indexing | 1 | 1 |
| Year of publication | 10 for the current year and −2 for each year in the past | 10 for the current year and −0.6 for each year in the past |
| Type of publication; for example, good practice guidelines, consensus statements, directives, literature reviews, and meta-analyses | 0 | 3 |
aMeSH: Medical Subject Headings.
bIn the field of biomedicine, articles are often indexed according to the MeSH thesaurus. LiSSa considers the MeSH terms to be major when they correspond to one of the article’s main themes or minor when they correspond to one of the article’s subthemes.
cThe MeSH thesaurus is structured like a tree; an MeSH term typically has several hierarchical levels above and below it. For example, asthma belongs to the bronchial diseases category and one of its narrower terms is status asthmaticus. A search for asthma will thus also find an article indexed as status asthmaticus but the latter will be less weighted because indexing is said to be exploded.
dSome documents are indexed by a National Library of Medicine indexer; this is referred to as manual indexing. Other documents are indexed by text mining tools, which is referred to as automatic indexing. Manual indexing is considered to be more accurate and efficient than automatic indexing.