User-Centred Requirements Handbook |
This method features the use of simple materials and equipment to create a paper-based simulation of an interface or system with the aim of exploring user requirements. (Later in the lifecycle, paper prototypes provide a valuable and cost-effective means to evaluate design options. Interface elements such as menus, windows, dialogues and icons are created using paper, card, acetate, and pens etc.) The result is sometimes referred to as a low-fidelity prototype. When the paper prototype has been prepared, a member of the design team sits in front of the user and 'plays the computer' by moving interface elements around in response to the user's actions. The user makes selections and activates interface elements by using their finger as a mouse and writing 'typed' input. A further person facilitates the session by providing task instructions and encouraging the user to express their thoughts and impressions. Notes may be made by other observers or a video recording can be made. Costs may also be incurred when recruiting users and allocating time to manage each evaluation session.
The method has wide applicability. However, it is most suitable in contexts where it is easy to simulate system behaviour or when the evaluation of detailed screen elements is not required. Paper prototyping is appropriate for the early stages of the design cycle where a range of user requirements and general system concepts can be explored easily and quickly.
Benefits
• Communication and collaboration between designers and users is encouraged.
• Paper prototypes are quick to build and refine.
• Only minimal resources and materials are required to convey product feel.
• The technique can be utilised by those with little or no human factors expertise.
Limitations
• Because of their simplicity, paper prototypes do not support the exploration of fine detail.
• Due to the use of paper and a human operator, this form of prototype cannot be reliably used to simulate system response times.
• The individual playing the role of the computer must be fully aware of the functionality of the intended system in order to simulate the computer.
What you need
Only simple materials are required to create the elements of the prototype. These include paper, acetate, pens and adhesives. 'Post-its' may also be used to represent interface elements such as system messages, input forms and dialogue boxes. A video camera may also required to record the paper-based interactions. The user session may employ two evaluators, one to manipulate the paper interface elements, acting as the system, and the other to control the session.
Process
The following procedure may be adopted for implementing this method:
1. Firstly, allow enough time to create the prototype, design some tasks, recruit users, conduct the evaluation of the prototype and report the results.
2. Assemble the necessary materials. Construct the paper prototype, using separate pieces for menus, dialogue boxes and any element that moves or changes appearance.
3. Select appropriate users to test the prototype. Try to cover the range of users within the target population.
4. Prepare realistic task scenarios for the evaluation.
5. Pilot the evaluation procedure and practice playing the role of the computer.
6. Ensure recording facilities are available and functioning.
7. Conduct each session by manipulating the paper prototype as the user works through the tasks.
8. The facilitator provides the task instructions and explores the user's impressions and intentions through appropriate questions.
9. If observers are present they can make notes of problem areas and potential solutions during the session for later scrutiny.
10. Conduct post-session interviews with the user, drawing upon pre-set questions and issues raised during the prototype evaluation.
11. Debrief and thank the user.
12. Analyse information obtained, summarise observations and user evaluations. Consider the themes and severity of the problems identified.
13. Summarise implications for user requirements and feed back to the design team. Video recordings can support this.
14. Where necessary, refine the paper prototype and repeat the above process.
Practical guidelines
• Work through the paper-based interactions as fully as possible and try to cover the different paths that users may wish to follow.
• Have spare paper, Post-its, etc. available to simulate new paths of interactions that the user would expect to make.
• Practice the possible interactions with a pilot user to make the interactive process as slick as possible.
Further information
Nielsen (1991), Rettig (1994).