Change awareness is the ability of individuals to track the asynchronous changes made to a collaborative document or graphical workspace by other participants over time. We develop a framework that articulates what change awareness information is critical if people are to track and maintain change awareness. Information elements include: knowing who changed the artifact, what those changes involve, where changes occur, when changes were made, how things have changed and why people made the changes. The framework accounts for people's need to view these changes from different perspectives: an artifact-based view, a person-based view and a workspacebased view. Each information element is further broken down into distinguishing features and matched against these perspectives, e.g., location history within the where category prompts the questions `where was this artifact when I left' in the artifact-based view, `where in the workspace has a person visited' in the person-bas...