Visual Representations as Feedback in a Programmable Visual Shell by Francesmary Modugno and Brad A. Myers} March 1993 Although visual shells (e.g., Apple Macintosh) are easy to use, they are difficult to program, especially by non-expert users. PURSUIT is a visual shell that contains a programming by demonstration (PBD) system to address this problem. In a PBD system, users execute actions on data and the underlying system attempts to construct a program. Such systems, however, have limitations: feedback is often difficult to understand, disruptive or non existent; and programs often have no representation for users to examine or edit. PURSUIT addresses these problems by presenting the inferred program in an editable {\it graphical} language {\it while it is being constructed}. The language is a state-based visual language in which icons represent objects such as files and folders and changes in these icons represent operations. The representations are similar to the objects and effects that users see in the real interface. This provides users with an immediate view of the code and feedback in a way that is familiar, easy to understand, and non-disruptive. An intuitive representation that also serves as feedback makes it easier for users to write programs to customize their systems.