PLUS: A provenance manager for integrated information

It can be difficult to fully understand the result of integrating information from diverse sources. When all the information comes from a single organization, there is a collective knowledge about where it came from and whether it can be trusted. Unfortunately, once information from multiple organizations is integrated, there is no longer a shared knowledge of the data and its quality. It is often impossible to view and judge the information from a different organization; when errors occur, notification does not always reach all users of the data. We describe how a multi-organizational provenance store that collects provenance from heterogeneous systems addresses these problems. Unlike most provenance systems, we cope with an open world, where the data usage is not determined in advance and can take place across many systems and organizations.