Guidelines for small and large touch screens

This part is addressed to other designers who are interested in designing applications for small and large touch screens. The next list will show short guidelines, which are based on the experiences of this work.

To keep general in mind:

• Read the Apple design guidelines. [See blog: iPhone – Elements, iPhone - Interaction Design Pattern, iPad - Interaction Design Pattern]
• Check other Apps, because the new design will be part of a whole user experience.
• Start with sketch and paper prototypes and involve very early in the design process possible users. [See blog: iPhone - quick usability test with a paper prototype, iPad - quick usability test with a paper prototype]
•  Think about smart interaction solutions with only some functional elements to have more designing room. [See blog: Video - final high fidelity prototypes]
• Work with metaphors, when possible. However be careful not to overload the design with too much imitation so that it becomes complicated to navigate (Stapelkamp 2007, p.155). Metaphors should support functions. [See blog: How to deal with a fullness of information?, iPhone - To keep in mind, Video - final high fidelity prototypes]
• When pictures are present in a concept use some with a high resolution.
• Work with space between the areas instead of lines and boxes.
• Have a good level of contrast and colour. [See blog: Excursus Colour and Contrast, Colour concept].

Designing for different screen sizes:

• Design first for the smaller screen size then for the larger sizes, because the limited sizes helps to focus. [See blog: Is it better to design first for a small screen and than for a larger screen or is it better the other way around?].
•  Fragment the content for the smaller screen and show them in a series of screens and integrate more content on a lager screen.
• Design for the smaller screen looks more functional and use for the larger screen has more realistic imagery and decorations.
• Do not use multi finger gestures such as drag and drop for a small screen such as the iPhone, but use the drag and drop gesture for a larger screen such as the iPad. However, check in a usability test if users are expecting the multi finger gestures. Because interaction gestures are sometimes not obvious when they are not learned. Maybe in the future multi finger gestures will be more common because more touch devices are on the market and people will learn the gestures. However, at the moment for novices it is especially hard to find access to new interaction element such as multi finger gestures. If gestures are not expected, do not use them or offer alternatives. 

Stapelkamp, T., 2007. Screen- und Interfacedesign: Gestaltung und Usability für Hard- und Software. Berlin: Springer-Verlag.