Enabling Multimodal Interaction in XPL – the eXtensible Presentation Language

This paper introduces the multimodal extension of the eXtensible Presentation architecture and Language (XPL), a framework aimed at streamlining multi-channel interface design process and enabling full component reuse. XPL incorporates a presentation language based on design pattern paradigm, which supplies a clear distinction between the presentation layer and the corresponding programming logic, promoting contents aggregation and a variety of event handlers described without relying on a (procedural) scripting language. In this paper, the design pattern concept is extended to voice-based interaction, and two Verbal Design Pattern (VeDP) are introduced along to their visual counterparts. This multimodal extension enables user interface designers to develop application interfaces for multiple access channels within a single development framework. To illustrate the benefits of using XPL in a large software design project, a case study, showing the development of user interfaces for a web-based application, is fully detailed.