Crowd learning can serve to educate the public and let children become investigators. Engaging with the crowd gives access to valuable sources of knowledge and opinion. A classic example of the crowd in action is Wikipedia, the online encyclopedia co-created and continually updated by the public. Crowdsourcing involves members of the public giving and receiving information to solve problems, create content, vote for the best solutions or raise funds. Online crowdsourcing platforms, such as Wikipedia, Reddit and IdeaScale, allow amateurs to exchange ideas with experts, combining wisdom of the crowds with expert knowledge and commentary. Citizen science is a form of crowdsourcing for scientific or research projects. Online citizen science sets up websites for mass participation in science activities. Applications of crowdsourcing in education include collecting and curating teaching resources, letting students share and discuss their work online and providing opinions and data for use in projects and research studies.