A wiki BarnRaising is a planned event in which a community meets at a designated time to build content on the wiki together. One person alone can't build all the content in a wiki, and a community of people needs to understand how to use the wiki, and feel a sense of buy-in for it to become successful. A BarnRaising achieves this because people come expecting to learn how to use the wiki, and they are able to interact with each other as they work, thus strengthening community bonds and creating a support network that keeps people using the wiki. - Chris Coyier