"People often criticize social media for facilitating the spread of misinformation. In this book, we define and describe the value of observed correction, which occurs when direct public corrections of misinformation are witnessed by others. We offer evidence that observed correction gives people a more accurate understanding of the topic, especially when they remember the corrections. We describe how lots of people - social media users, public health experts, and fact checkers among them - are conflicted or constrained correctors. They think correction is valuable and want to do it well, even as they raise real concerns about the risks and downsides of doing so. We demonstrate that simple messages addressing these concerns can make people more willing to respond to misinformation. Mitigating other concerns will require real changes to the very structure of social media and society, and for that reason we need everyone to work together to make observed correction more impactful. Experts should contribute by creating accessible curated evidence (ACE) to facilitate user corrections and correcting publicly to build social norms around responding to misinformation. Platforms should promote corrections and take action against toxic behaviors. Users should feel empowered to correct misinformation when they feel comfortable and confident. Fundamentally, observed correction is an important tool in the fight against misinformation because it is effective and can be scalable if more people are willing to do it"-- Provided by publisher.