In human–computer interaction, paper prototyping is a widely used method in the user-centered design process, a process that helps developers to create software that meets the user's expectations and needs - in this case, especially for designing and testing user interfaces. It is throwaway prototyping and involves creating rough, even hand-sketched, drawings of an interface to use as prototypes, or models, of a design. While paper prototyping seems simple, this method of usability testing can provide a great deal of useful feedback which will result in the design of better products. This is supported by many usability professionals.
Paper prototyping started in the mid 1980s and then became popular in the mid 1990s when companies such as IBM, Honeywell, Microsoft, and others started using the technique in developing their products. Today, paper prototyping is used widely in user centered design by usability professionals. More recently, digital paper prototyping has been advocated by companies like Pidoco due to advantages in terms of collaboration, flexibility and cost.
Paper prototyping saves time and money since it enables developers to test product interfaces (from software and websites to cell phones and microwave ovens) before they write code or begin development. This also allows for easy and inexpensive modification to existing designs which makes this method useful in the early phases of design. Using paper prototyping allows the entire creative team to be involved in the process, which eliminates the chance of someone with key information not being involved in the design process. Another benefit of paper prototyping is that users feel more comfortable being critical of the mock up because it doesn’t have a polished look.
There are different methods of paper prototyping, each of them showing several benefits regarding the communication within the development team and the quality of the product to be developed: In the development team paper prototypes can serve as a visual specification of the graphical user interface, and by this means assure the quality of a software. Prototyping forces a more complete design of the user interface to be captured. In team meetings they provide a communication base between the team members. Testing prototypes at an early stage in development helps to identify software usability problems even before any code is written. The costs and annoyances of later changes are reduced, the support burden is lowered, and the overall quality of the software or website is increased.
When to use paper prototypes 
Paper prototypes should be considered when the following is true:
- When the tools the designer wants to use in creating a prototype are not available.
- When the designer wants to make a sincere effort to allow all members of a team, including those with limited software skills, to take part in the design process.
- When tests of a design lead to a great deal of drawings.
Applying paper prototypes 
The most important areas of application of paper prototypes are the following:
- Communication in the Team
- One of the major applications of paper prototyping is brainstorming in the development team, to collect and visualise ideas on how an interface might look. The interface is built up step by step, meeting the expectations of all team members. To probe the applicability of the software design, typical use cases are played through and possible pitfalls are identified. The prototype can then be used as a visual specification of the software.
- Usability Testing
- Paper prototypes can be used for usability testing with real users. In such a test, the user performs realistic tasks by interacting with the paper prototype. The prototype is manipulated by another person reflecting the software's reactions to the user input actions. Though seemingly unsophisticated, this method is very successful at discovering usability issues early in the design process.
- Three techniques of paper prototyping used for usability testing are comps (short for compositions), wireframes, and storyboards. Comps are visual representations, commonly of websites, that demonstrate various aspects of the interface including fonts, colors, and logos. A wireframe is used to demonstrate the page layout of the interface. Lastly, the storyboards are a series or images that are used to demonstrate how an interface works. These three techniques are useful and can be turned into paper prototypes.
- Design testing
- Especially in web design, paper prototypes can be used to probe the illegibility of a design: A high-fidelity design mockup of a page is printed and presented to a user. Among other relevant issues the user is asked to identify the main navigation, clickable elements, etc. Paper prototyping is also the recommended design testing technique in the contextual design process.
- Information architecture
- By applying general and wide paper prototypes, the information architecture of a software or web site can be tested. Users are asked where they would search for certain functionality or settings in software, or topics in a web site. According to the percentage of correct answers, the information architecture can be approved or further refined.
- Rapid prototyping
- Paper prototyping is often used as the first step of rapid prototyping. Rapid prototyping involves a group of designers who each create a paper prototype and test it on a single user. After this is done, the designers share their feedback and ideas, at which point, each of them creates a second prototype - this time using presentation software. Functionality is similarly unimportant, but in this case, the aesthetics are closer to the final product. Again each designer's computer prototype is tested on a single user, and the designers meet to share feedback. At this point, actual software prototypes can be created. Usually after these steps have been taken, the actual software is user-friendly the first time around, which saves programming time.
See also 
- Paper Prototyping Article
- Marc Rettig (1994): Paper Prototyping for Tiny Fingers. One of the core articles used to describe the principles of paper-prototyping.
- 1 Sefelin, R., Tscheligi, M., & Giller, V. (2003). Paper Prototyping – What is it good for? A Comparison of paper – and Computer – based Low fidelity Prototyping, CHI 2003, 778-779. portal.acm.org
- 2 Snyder, Carolyn (2003). Paper Prototyping: the fast and easy way to design and refine user interfaces. San Francisco, CA: Morgan Kaufmann.
- 3 Snyder, Carolyn: Paper Prototyping: the fast and easy way to design and refine user interfaces http://paperprototyping.com/
- 4 Klee, M. 2000. Five paper prototyping tips. Available from User Interface Engineering.
- 5 Arnowitz, J., Arent, M., Berger, N., (2007) Effective Prototyping for software makers. Morgan Kaufmann