DESIGNING INTERACTIVE USER INTERFACES: DIALOG CHARTS AND AN ASSESSMENT OF THEIR USE IN SPECIFYING CONCEPTUAL MODELS OF DIALOGS

Abstract

The conceptual design of user interfaces focuses on arriving at a specification of the structure of the dialog, independent of any particular implementation approach. There is common agreement as to the importance of this activity to both IS professionals and end-users, but few -- if any -- modeling methods were developed to specifically support the process of conceptual design, and the usefulness of such methods has not been adequately addressed. This paper introduces the Dialog Charts (DCs), and documents a preliminary examination of their perceived usefulness by designers of user/system interaction who actually used them. The DCs yield high level dialog schemas that are abstract enough to support the conceptual design of dialog control structures. In a uniform diagramming framework they combine the concept of dialog independence, distinguish between the dialog parties, provide for hierarchical decomposition and enforce a structured control flow. The usefulness of the DCs has been studied empirically in a qualitative inquiry. Recalled experiences of designers were captured and analyzed to ascertain the concept of usability, as well as assess the usability of the DCs. Usability has emerged from this study as a set of 38 concerns that operationalizes the broader aspects of purpose of use, design stage, impact on product structure, impact on design process, and attitudinal patterns. In general, the Dialog Charts were found by these dialog designers to be a useful, exhibiting the essential attributes of tools for conceptual modeling.