Tracking Information Johan van Benthem Abstract: Depending on a task at hand, information can be represented at different levels, less or more detailed, each with their own appropriate logical languages. We discuss a few of these levels, and their connections, and how information growth at one level can be tracked at another. The resulting view has two intertwined dynamics for informational agents: one of update and one of representation. Note: The final version of this paper will appear in the 2016 volume for Michael Dunn in the Springer series "Outstanding Contributions to Logic", edited by Katalin Bimbo.