In Team Settings, you can assign roles to particular reviewers for screening (eg, 1 person must screen every study, but any second person can be the 2nd vote), as well as for resolving conflicts.
When multiple screeners are working simultaneously, it is possible that reviewers might end up screening the same item at the same time. Some strategies to avoid this scenario include frequently refreshing the page, and changing the order in which results display (eg one screener might sort by relevancy, another by author, etc)
