This paper addresses the problem of the graceful degradation of user interfaces where an initial interface is transferred to a smaller platform. It presents a technique for pagination of interaction spaces (e.g., windows, dialog boxes, web pages) based on a multi-layer specification in the user interface description language UsiXML. We first describe how an interaction space can be split using information from the presentation layer (Concrete User Interface). We then show how information from higher abstraction levels (Abstract user Interface, Task model) can be used to refine the process. This technique belongs to a collection of transformation rules that have been developed to adapt a user interface to smaller, more constrained displays. Categories and Subject Descriptors D.2.2 [Software Engineering]: Design Tools and Techniques – User interfaces. H.5.2 [Information Interfaces and Presentation]: User Interfaces – Graphical user interfaces. General Terms Design, Human Factors, La...