TECHNIQUES FOR DESIGN AND TEST
Interaction designing is predicated on a belief in trial and error, using prototyping and mock-ups to test new design ideas. IDEO’s ‘Try’ cards suggest methods to inform design decisions as the development of a new product progresses. These methods or strategies focus on user input, feedback, and responses as they attempt to use a new technology to achieve some goal. The methods stimulate and simulate users’ experiences, feelings, and perceptions in ways that are quite often completely absent or ignored in traditional product design projects. Among these techniques ‘prototyping’ in all its various guises is particularly valued by both developers and users as they grapple with the challenge of designing interaction between user and technology (Moggridge, 2006).
Table: IDEO ‘Try’ techniques (IDEO, 2003)
“Paper prototyping is a variation of usability testing where representative users perform realistic tasks by interacting with a paper version of the interface that is manipulated by a person 'playing computer,' who doesn’t explain how the interface is intended to work.” (Snyder, 2003)One of the perpetual challenges of high tech systems development is the cost of up-front design. High tech products and services have highly intangible qualities across a number of dimensions; in terms of time to deliver, dependence on other technologies, flexibility of the realization (product), dependence on rare skills and expertise. High tech products and services are themselves highly virtualized constructs or dependent themselves on the features of intangible goods; source code through to compiled application is a digital media, brittle, and based on architectural concepts that are difficult to represent, interpret and understand. Consequently high tech systems are associated with large up-front development costs before the product is usable or even visible. Compounding the problem is the observation that over 90% of a digital good’s implementation is manifest in the arcane digital back-end consisting of software architecture and computing infrastructure. The most visible aspect of a high tech product, its interface and user interaction driven aspects are a small fraction of the overall implementation. The interface is also often the last aspect to be finished for a high tech system. This delay between the conceptual ‘idea’ of the system and its eventual implementation ends up compounding the risk of systems development projects because late changes to user and interaction interfaces often necessitate fundamental redesigns of the underlying back-end architecture. All of this can be avoided with early interaction design.
Paper prototyping is one of many techniques that can and should be employed as early as possible in the development process to trial and refine design ideas surrounding user interaction. Paper prototyping is a method for rapidly constructing product mock-ups that are manipulated by users (but managed by a ‘computer’) to demonstrate design concepts and raw functionality. Paper prototyping and associated techniques for mocking up a system prototype (Table below) are effective ways of simulating and articulating design concepts with users.
Table: Some visual prototyping tools for design (Snyder, 2003)
Paper prototyping is used to ‘enact’ system walkthroughs, of either the whole product or a single feature. They help to identify user paths through the system and can highlight parts that aren’t usable, accessible or that don’t work as users expect them to. Paper prototyping enables fast feedback on technical requirements and the feasibility of different design concepts. A paper prototyping walkthrough session can use the following roles: computer, expert user, scribe, and facilitator. (Exhibit below) Usability tests and pilot tests are simply more elaborate walkthroughs, with progressively fewer in-place supports for users and progressively less flexibility in reconfiguring the simulation.
EXHIBIT: Paper prototyping walkthrough session roles (Snyder, 2003)
Computer. The person who organizes and manipulates all those bits of paper (may be more than one person).
Expert user. A product team member plays this role, performing the tasks as an expert (someone who understands the interface) would be expected to do. It’s not part of this role to make bizarre mistakes or other radical departures from the norm – leave that for the real users!
Scribe. This person writes down all the missing pieces, issues, and questions that come up. It’s not always the best use of time for the entire team to discuss each issue on the spot and come to a decision. The scribe makes a list so that these things can be addressed after the walkthrough. On small teams, the scribe role may be combined with any of the other roles.
Facilitator. Strictly speaking, a walkthrough doesn’t need a facilitator, although it doesn’t hurt to have a designated person lead the session and make sure it doesn’t digress too much. Whoever plans to facilitate the usability tests should attend some walkthroughs in preparation; walkthroughs are a great way to become familiar with the functionality and behavior of the interface. For new facilitators, it’s also an opportunity to practice.