DDUAC04This paper describes the Interactive Document Summariser (IDS). IDS provides dynamic control over document summary characteristics, such as length and topic focus, so that changes made by the user are instantly reflected in an on-screen summary. "Summary-in-context views allow users to move flexibly between summaries and their source documents. IDS adopts the technique of sentence extraction, exploiting keyphrases that are automatically extracted from document text as the primary attribute of a sentence extraction algorithm. We report an evaluation of IDS summaries, in which representative end-users of on-line documents identified relevant summary sentences in source documents. IDS summaries were then compared to the recommendations of the users and we report the efficacy of the summaries based on standard precision and recall measures. In addition, using established evaluation metrics we found that IDS summaries were better than baseline summaries based on within-document sentence ordering.