We present the concept of ZOOM NAVIGATION, a new interaction paradigm to cope with visualization and navigation problems as lound in large information and application spaces. It is based on the pluggab/e zoom, an object-oriented component derived lYom the variable zoom fisheye algorithm.Working with a limited screen space we apply a degree-q/L interest (DOI) fimction to guide the level of detail used in presenting information. Furthermore we determine the user's information and navigation needs by analysing the interaction history. This leads to the definition of the aspect-q/Linteres't (AOI) function. The AOI is evaluated in order to choose one of the several inlbrmation aspects, under which an item can be studied. This allows us to change navigational q[/brdanee and thereby enhance navigation.In this paper we describe the ideas behind the pluggable zoom and the definition of DO1 and AOI functions. The application of these fimctions is demonstrated within two case studies, the ZOOM ILLUSTRATOR and the ZOOM NAVIGATOR. We discuss our experience with these implemented systems.