From: Boolean versus ranked querying for biomedical systematic reviews
 |  |  | Simplified | ||
---|---|---|---|---|---|
 | Original | Ovid | Lucene | ||
Query | all | unique | all | unique | Â |
1 | 2,153 | 1,986 | 29,074 | 15,027 | 7,654 |
2 | 1,378 | 1,347 | 120,420 | 111,653 | 1,596 |
3 | 101 | 101 | 1,857 | 1,799 | 1,568 |
4 | 994 | 897 | 12,857 | 11,924 | 81,371 |
5 | 1,526 | 1,343 | 63,494 | 53,319 | 8,093 |
6 | 276 | 276 | 159,772 | 153,121 | 36,686 |
7 | 1,200 | 1,117 | 109,584 | 104,743 | 308,329 |
8 | 309 | 230 | 106,154 | 81,018 | 64,704 |
9 | 1,464 | 1,464 | 41,544 | 35,618 | 17,686 |
10 | 64 | 64 | 2,260 | 2,205 | 243,733 |
11 | 930 | 540 | 6,420 | 6,172 | 23,896 |
12 | 140 | 140 | 3,215 | 3,058 | 1,599 |
13 | 5,578 | 5,378 | 21,332 | 20,588 | 13,491 |
14 | 1,969 | 1,782 | 39,446 | 36,487 | 24,230 |
15 | 997 | 997 | 9,859 | 9,568 | 5,189 |