A prosodic user interface is defined as an user interface that can deal with not only what is entered by the user but also how it is entered. A pen-based user interface provides more prosodic information than a mouse-based graphical user interface. The need for a pen-based prosodic user interface in an educational application domain is argued. As a simple example of a pen-based prosodic user interface, the notion of a positional handwriting recognizer is introduced and its implementation discussed.