"This Synthesis Report examines the effectiveness of countermeasures against misinformation on social media platforms, focusing on the two most examined remedies: content labeling and corrective information interventions. A meta-analysis is a research process for synthesizing and aggregating the findings of many, independent studies, using statistical methods to calculate overall effects from multiple data sources. A meta-analysis of 43 studies from 18 peer-reviewed manuscripts was selected from a comprehensive database of 4,798 publications. First, there is an emerging scientific consensus that content labels and corrective information help people evaluate misinformation on social media platforms. Other mitigation strategies may be viable, but there is less consensus about their effectiveness. Second, understanding the global information environment requires more research: (i) from countries around the world, (ii) about user experiences in languages other than English, (iii) with genuine access to social media data from firms, (iv) that allows scientists to standardize measures and definitions for robustly reporting the results of independent research." (Synopsis)