Interactions - July/August 2009

Inspection Usability Testing

Field Study

Inspection Usability Testing

• Figure 1. “Paper in Screen” enables anticipating the evaluation of the mobile user experience. This can happen long before a high-fidelity prototype has been integrated into a mobile device.

July + August 2009

to another. This sequential navigation can be easily controlled through the most elementary interaction command available on a mobile device (tapping, sliding, flipping, or using a single button). In other words, the papers are not made interactive, but they become interactive on a more generic and basic level through the use of a standard device command. With minimal initial explanation, users point their finger on the actual interface link they need to activate and slide/ flip the screen to move to the next page. The digital paper prototype is still provisional, malleable, thought provoking, and expressive, but at the same it enables the user to experience it within the real mobile device, with all its affordances for an interaction experience that is both tactile and visceral. And all this can be done at a very limited cost.

interactions

forward technique: placing the paper prototype inside the device. It is possible to quickly generate a paper prototype (using traditional guidelines and best practices) and efficiently digitalize it in a form suitable for integration and interaction within a mobile device (see page 29). Designers can then ask users to use an actual mobile device (e.g., an iPhone) to try out the prototype, by looking at and flipping through the digitalized papers, thus envisioning a richer mobile experience.

The “paper in screen” approach has important benefits. Users can hold the actual mobile device while interacting with the digitalized paper prototype. And users can interact with the digital prototype in a way that is intimately integrated with the physical experience, thus capturing a fully emotional and true-to-life usage.

The only drawback (to meet the requirements of an “agile” prototype generation) is that the digitalized paper is not fully interactive. The only supported interaction is moving from one screen

From Interface to Experience Prototyping The cost and feasibility of the paper-in-screen approach should be considered in the context of

the design life cycle. In a simplified picture of the established practice of interactive application development, iterations often occur between the experience design and interface evaluation (see Figure 2). Paper prototypes typically serve well in this phase; they can cheaply externalize the reification of the design vision into an interface, more or less refined. Paper-based interface prototyping easily lends itself to a subsequent usability evaluation that can be done through various techniques (usability tests, inspections, or walkthrough). Besides the important details of the interface elements, the conceptual flow of the overall navigation and task support can be evaluated. Still, everything is focused solely on the interface as an artificially separate artifact from the overall user experience. After a reasonable number of insightful iterations, low-fidelity paper prototypes are typically improved, refined, and eventually solidified into more interactive, electronic, partially implemented applications that can be integrated as they are into a mobile device for more lively validation and demonstration. This is the stage in which users can actually try out a mobile application using a real device, and designers are able to finally evaluate their user experience. Besides full usability inspection and lab testing, on-the-field observations can be performed, as all the enabling elements of the user experience are there. Using “paper in screen” provides a straight shortcut to make this process much more efficient (see Figure 1).