These systematic violations can be used to identify whether an action or condition causes a certain effect (high lead - blood levels causing ADHD) from large enough sample sizes of observational data. (sciencedaily.com)
The TIMSS tests were administered to students in 63 countries and 14 regions, including nine U.S. states that were able to submit large enough sample sizes to be included. (ascd.org)
After eliminating duplicate studies, those with nonstandard measures and those that failed to include control subjects or large enough sample sizes, the team ended up with a total of 67 studies, with 16 of them focused on traditional Chinese medicine. (sciencedaily.com)