It is often said that users cannot tell you what they want. But they can let you know what they like and what they don't like when they get to see and use a prototype (Preece et al. p.386). Prototyping is a process of getting design ideas out of your head and into the physical world. A prototype can be anything that takes a physical form—be it a role-playing activity, physical space, an object, a software interface, or even a storyboard. The resolution of your prototype should be commensurate with your progress in your project. In early explorations, keep your prototypes rough and rapid to allow yourself to learn quickly and investigate a lot of different possibilities (d.school 2010). Later on, you create more refined, higher-fidelity prototype.

Prototypes should facilitate communication between the various stakeholders in the design process. When there is no existing physical design to focus on, discussions between stakeholders (e.g., users, clients, and your teammates) often go nowhere. When a prototype exists, it’s possible to have meaningful conversations. The prototype embodies a design hypothesis that stakeholders can test and measure against their own criteria. And when conflicts occur, they can be more easily resolved. So, good prototypes should not be required to be complete. It is normal for a prototype to be imperfect as its role is to invite discussion among stakeholders. And it should be easy and cheap to change because you’ll want to experiment with as many design variations as you can without building an entirely new prototype. Good prototypes get to retire. A prototype should not outlive its usefulness; once you have learned the pros and cons of the design space explored with the prototype, you should not keep that prototype.

Low-fidelity Prototyping Techniques

User-centered design promotes making quick-and-dirty prototypes in the early stage of the the design process. Fidelity refers to the quality of prototype, so quick-and-dirty prototypes are often called low-fidelity/lo-fi prototypes. Commonly used low-fidelity prototyping techniques are:

[From Storyboarding to Drawing Wireframes | Google UX Design Certificate (24:27-) Source: https://youtu.be/WyXTT30YFjI?t=1467](https://youtu.be/WyXTT30YFjI?t=1467)

From Storyboarding to Drawing Wireframes | Google UX Design Certificate (24:27-) Source: https://youtu.be/WyXTT30YFjI?t=1467

Paper prototype: Paper prototyping offers a rapid way to work through every detail of the interaction design across multiple applications. When you show users a polished-looking prototype, they tend to offer their opinions about issues related to polish (e.g., “I don’t like the font” or “this button looks like it should be 5 pixels to the left.”). This kind of feedback is not so useful early in the design process. Using a paper prototype prevents people from giving feedback on issues related to polish and help them focus their attention on the issues that matter most in early stages (i.e., does the prototype suffice users’ needs).

[Hanmail Paper Prototype UX (User Experience). Source: https://youtu.be/GrV2SZuRPv0](https://youtu.be/GrV2SZuRPv0)

Hanmail Paper Prototype UX (User Experience). Source: https://youtu.be/GrV2SZuRPv0

Wizard-of-Oz: In this technique, the user interacts with the software as though interacting with the product. In fact, however, a human operator simulates the software’s response to the user input (Preece et al. 2015). We often use Wizard-of-Oz together with the paper prototypes.

[How to Create a UX Storyboard. Source: https://youtu.be/bNh54LNUtv8](https://youtu.be/bNh54LNUtv8)

How to Create a UX Storyboard. Source: https://youtu.be/bNh54LNUtv8

Storyboard: A storyboard is like a comic strip or comic book. It’s a series of panels that tells a story in pictures. It is a low-fidelity prototyping technique that combines scenarios and sketches. A storyboard consists of a series of sketches showing how a user might progress through a task using the product under development.
Navigational Diagrams: Depending on a type of your application, how mobile/web interface views are organized or how information is accessed might differ. You can organize the structure of the site's contents using a site map, how a series of instructions are presented using a flow chart, or represent relationship between entry points (e.g., search engine, social media) and site's contents.

Make a Lot of Prototypes

https://www.youtube.com/watch?v=vQyrMMAbXgc&ab_channel=StevenDow

A generally accepted good practice for prototyping is to make a lot of them. Making a lot of prototypes and testing them with users allow you to learn what design works and what doesn't. It forces you to explore a broad design space for implementing a design idea, again, giving you an opportunity to reflect on what could be good and bad design.

We should intentionally force ourselves to create many prototypes also because of our psychological tendency called functional fixation. Our tendency to being fixated means that we tend to pick a design introduced early in the process and stick to it. To break out of this tendency, we should force ourselves to explore as much design space as possible to test diverse design ideas (Dow et al. 2010).

Figure from Bill Buxton's "Sketching user experiences"

In his book "Sketching user experiences", Bill Buxton note that the core of design consists of cycles of elaboration followed by reduction. He says, “Design is choice, and there are two places where there is room for creativity: the creativity that you bring to enumerating meaningfully distinct options from which to choose the creativity that you bring to defining the criteria, or heuristics, according to which you make your choices”. That is, in elaboration, you should generate multiple possible solutions to a problem, and in reduction, you select desirable solutions from that set. The book encourages you to alternate and repeat the two steps at different granularities. You should initially create many low fidelity prototypes, and as the design process progresses, create higher fidelity prototypes.

What to Test

If you still feel that making prototypes is a waste of time, then maybe it’s because you’re falling into one of the classic blunders: functional fixation. Many novices approach a design problem by stumbling upon a design that seems to work and then arguing for that design. A better approach is to set measurable goals for a design. If you have a way to compare the quality of different designs, then it helps you to see that most designs can be improved. Having measurable goals also helps you to see when goals come into conflict. When you discover this, you can set priorities and think about the tradeoffs in different designs.

There are three main aspects of a prototype that you should test: form, function, and experience (Houde and Hill 1997).

Function: Function refers to the role that the interactive system plays in a users’ life. You should question how the interactive system that you are prototyping enrich the users’ life or solve problems they have.
Form: Look and feel of the interactive system. It lets you ask questions about the concrete sensory experience of using the interactive system—how it looks and what do people hear while using it.
Experience: You should ask if the interactive experience of using the system be pleasant and satisfy what the users would expect in prototyping the interactive artifact.

The questions that you will ask in the subsequent step of the design cycle will take forms like “will changing the form factor of this user interface improve its usability?” or “will offering this functionality make the system more useful?” Although asking these questions is a part of the testing mode, you should have an idea of what you will be testing while you are prototyping.