The system comprises an improved document monitoring agent in which user evaluations are used to decide whether a changed document should be saved in the system or not. The evaluation of importance of the change in a document is performed by one or more users who collaboratively monitor a networked document, typically identified by a URL. By providing a user evaluation interface, it is possible for users to indicate their evaluation of the significance of the change. As such, only significantly changed documents, as indicated by the users themselves, are saved. Thus, a more efficient saving is obtained while at the same time reducing the risk of discarding potentially interesting changed documents which would have been discarded by conventional monitoring agents.