Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Precision of each search strategy.
| Search strategy | Median (%) | Interquartile range (%) | Mean rank (Friedman test) | Reviews with precision < 1% (%) | Total retrieval size (across 61 reviews) |
| SS123 | 0.54 | 1.87 | 1.02 | 59.02 | 508625 |
| SS12 | 1.68 | 5.55 | 5.17 | 34.43 | 151691 |
| SScrossover | 1.68 | 5.54 | 4.24 | 34.43 | 152662 |
| SSCROSS-OVERSTUDIES | 1.68 | 5.55 | 4.77 | 34.43 | 151844 |
| SSvolunteer | 1.68 | 5.51 | 3.52 | 34.43 | 152880 |
| SSversus | 1.48 | 5.04 | 2.29 | 36.07 | 171032 |
χ2 = 258.634, p < .01
