Wednesday August 29th, 2012 by Heiko Tietze and Bj√∂rn Balazs
A policy how to design software or a ‘styleguide’ serves different purposes. On the one hand it tries to provide a consistent look and feel across the application by systematically allocating look, labels and wording and by applying a consistent style. Next to these rather design oriented aspects, the layout, fragmentation of the application and the kind of interaction should be alike across different modules, which can be reached by usability engineering activities. Within a consistent application it is easy to deduce from a known part to something new. These deductions are the groundwork for human thinking: We learn by generalizing what we experienced and by applying our previous experiences to new situations.
Especially producer of operating systems get confronted with a large amount of different applications and have hence started early to develop styleguides. There are elaborated versions for Microsoft Windows, Mac OS X and Android, but also community created versions in the area of open source like the Gnome Human Interface Guideline and the KDE Human Interface Guidelines. These guidelines are usually well elaborated but often do not match scientific standards. Evidence for the underlying assumptions, verifiable studies and publication about the topic are rare.
In the context of styleguides the term ‘User Experience’ is often used. It derives from the areas of webdesign and accounts for both, the aspects of design and usability. A large variety of possible presentations and quickly evolving standards necessitate the need for styleguides in these areas particularly, so the consistency on a webpage can be preserved for a longer time. To achieve this, Baxley introduced a model that comes closer to scientific criteria. This model provides a scientific basis for the development of company specific styleguides.
This ‘Universal Model of a User Interface’ consists of the three levels structure, behavior and presentation:
- With the structure of an application Baxley subsumes the conceptional model as a metaphor of the web page, the course of processing the tasks and the organizational model in terms of the generic flow of information.
- At the level of behavior he differentiates between viewing and navigation, editing and manipulation and user assistance.
- Presentation consists of layout, style and text.
The special charm of the model lies within the differentiation of the levels: While the presentation is most obvious to the user (and is reason for most discussions), this aspect is of less interest for the actual use – a badly drafted application will not improve by adding a pretty design. But these conceptual questions are often addressed insufficiently when planning the development and result in high efforts when reviewing the result.
Together with Swisslab we developed a stylegude based on the model from Baxley; however, not for a webpage but for desktop application. It turns out that the trichotomy is very useful here as well:
- Structure defines the vision of the application, who uses the program in which situations and the fundamental composition. Especially the division in concept, workflow and flow of information reveals improvement opportunities for the company.
- Behavior describes control elements like in conventional styleguides. In opposition to a web page the fragmentation does not apply to desktop application to the same extent as all control elements are also supportive and many can also be used for editing and manipulation. We therefore introduced an additional level based on psychologic considerations:
- ‘General navigation and grouping’ for the area ‘viewing and navigation’;
- ‘Selection, free and constrained input’ for ‘editing and manipulation’ and
- ‘User initiated information, system driven warnings and disruptive notifications’ for support
- The third level presentation again can be well adopted even though style in the connotation of branding is of little importance for a highly specialized application.
The model can hence be used for desktop applications with only little adaptations. The wisely chosen areas ease analysis and the result is geared to the target groups of the sytleguide:
- The level structure for usability experts,
- The level behavior for developer and
- The level presentation for designer and writer.