ata are provided as such, without any warranty of consistency from the provider, and the retrievers have to make it consistent before introducing it into their own databases. Other frameworks are also different in this respect: neither the knowledge sharing (when the opportunity to modify the shared knowledge is considered) nor the software agents provide any warranty about the consistency of the knowledge they provide.
L. von Ahn, M. Kedia, and M. Blum. CHI '06: Proceedings of the SIGCHI conference on Human Factors in computing systems, page 75--78. New York, NY, USA, ACM Press, (2006)