Using paper prototypes in UX

OptimalSort

8 min read Ania Mastalerz

In UX research we are told again and again that to ensure truly user-centered design, it’s important to test ideas with real users as early as possible. There are many benefits that come from introducing the voice of the people you are designing for in the early stages of the design process. The more feedback you have to work with, the more you can inform your design to align with real needs and expectations. In turn, this leads to better experiences that are more likely to succeed in the real world.

It is not surprising then that paper prototypes have become a popular tool used among researchers. They allow ideas to be tested as they emerge, and can inform initial designs before putting in the hard yards of building the real thing. It would seem that they’re almost a no-brainer for researchers, but just like anything out there, along with all the praise, they have also received a fair share of criticism, so let’s explore paper prototypes a little further.

What’s a paper prototype anyway?

Paper prototyping is a simple usability testing technique designed to test interfaces quickly and cheaply. A paper prototype is nothing more than a visual representation of what an interface could look like on a piece of paper (or even a whiteboard or chalkboard). Unlike high-fidelity prototypes that allow for digital interactions to take place, paper prototypes are considered to be low-fidelity, in that they don’t allow direct user interaction. They can also range in sophistication, from a simple sketch using a pen and paper to simulate an interface, through to using designing or publishing software to create a more polished experience with additional visual elements.

Different ways of designing paper prototypes, using OptimalSort as an example

Showing a research participant a paper prototype is far from the real deal, but it can provide useful insights into how users may expect to interact with specific features and what makes sense to them from a basic, user-centered perspective. There are some mixed attitudes towards paper prototypes among the UX community, so before we make any distinct judgements, let’s weigh up their pros and cons.

Advantages

They’re cheap and fast
Pen and paper, a basic word document, Photoshop. With a paper prototype, you can take an idea and transform it into a low-fidelity (but workable) testing solution very quickly, without having to write code or use sophisticated tools. This is especially beneficial to researchers who work with tight budgets, and don’t have the time or resources to design an elaborate user testing plan.
Anyone can do it
Paper prototypes allow you to test designs without having to involve multiple roles in building them. Developers can take a back seat as you test initial ideas, before any code work begins.
They encourage creativity
From both the product teams participating in their design, but also from the users. They require the user to employ their imagination, and give them the opportunity express their thoughts and ideas on what improvements can be made. Because they look unfinished, they naturally invite constructive criticism and feedback.
They help minimize your chances of failure
Paper prototypes and user-centered design go hand in hand. Introducing real people into your design as early as possible can help verify whether you are on the right track, and generate feedback that may give you a good idea of whether your idea is likely to succeed or not.

Disadvantages

They’re not as polished as interactive prototypes
If executed poorly, paper prototypes can appear unprofessional and haphazard. They lack the richness of an interactive experience, and if our users are not well informed when coming in for a testing session, they may be surprised to be testing digital experiences on pieces of paper.
The interaction is limited
Digital experiences can contain animations and interactions that can’t be replicated on paper. It can be difficult for a user to fully understand an interface when these elements are absent, and of course, the closer the interaction mimics the final product, the more reliable our findings will be.
They require facilitation
With an interactive prototype you can assign your user tasks to complete and observe how they interact with the interface. Paper prototypes, however, require continuous guidance from a moderator in communicating next steps and ensuring participants understand the task at hand.
Their results have to be interpreted carefully
Paper prototypes can’t emulate the final experience entirely. It is important to interpret their findings while keeping their limitations in mind. Although they can help minimize your chances of failure, they can’t guarantee that your final product will be a success. There are factors that determine success that cannot be captured on a piece of paper, and positive feedback at the prototyping stage does not necessarily equate to a well-received product further down the track.

Improving the interface of OptimalSort, one prototype at a time

We recently embarked on a research project looking at the user interface of our card-sorting tool, OptimalSort. Our research has two main objectives — first of all to benchmark the current experience on laptops and tablets and identify ways in which we can improve the current interface. The second objective is to look at how we can improve the experience of card sorting on a mobile phone. Rather than replicating the desktop experience on a smaller screen, we want to create an intuitive experience for mobiles, ensuring we maintain the quality of data collected across devices.

Our current mobile experience is a scaled down version of the desktop and still has room for improvement, but despite that, 9 per cent of our users utilize the app. We decided to start from the ground up and test an entirely new design using paper prototypes. In the spirit of testing early and often, we decided to jump right into testing sessions with real users. In our first testing sprint, we asked participants to take part in two tasks. The first was to perform an open or closed card sort on a laptop or tablet. The second task involved using paper prototypes to see how people would respond to the same experience on a mobile phone.

Context is everything

What did we find? In the context of our research project, paper prototypes worked remarkably well. We were somewhat apprehensive at first, trying to figure out the exact flow of the experience and whether the people coming into our office would get it. As it turns out, people are clever, and even those with limited experience using a smartphone were able to navigate and identify areas for improvement just as easily as anyone else. Some participants even said they prefered the experience of testing paper prototypes over a laptop. In an effort to make our prototype-based tasks easy to understand and easy to explain to our participants, we reduced the full card sort to a few key interactions, minimizing the number of branches in the UI flow. This could explain a preference for the mobile task, where we only asked participants to sort through a handful of cards, as opposed to a whole set.

The main thing we found was that no matter how well you plan your test, paper prototypes require you to be flexible in adapting the flow of your session to however your user responds. We accepted that deviating from our original plan was something we had to embrace, and in the end these additional conversations with our participants helped us generate insights above and beyond the basics we aimed to address. We now have a whole range of feedback that we can utilize in making more sophisticated, interactive prototypes.

Whether our success with using paper prototypes was determined by the specific setup of our testing sessions, or simply by their pure usefulness as a research technique is hard to tell. By first performing a card sorting task on a laptop or tablet, our participants approached the paper prototype with an understanding of what exactly a card sort required. Therefore there is no guarantee that we would have achieved the same level of success in testing paper prototypes on their own. What this does demonstrate, however, is that paper prototyping is heavily dependent on the context of your assessment.

Final thoughts

Paper prototypes are not guaranteed to work for everybody. If you’re designing an entirely new experience and trying to describe something complex in an abstracted form on paper, people may struggle to comprehend your idea. Even a careful explanation doesn’t guarantee that it will be fully understood by the user. Should this stop you from testing out the usefulness of paper prototypes in the context of your project? Absolutely not. In a perfect world we’d test high fidelity interactive prototypes that resemble the real deal as closely as possible, every step of the way. However, if we look at testing from a practical perspective, before we can fully test sophisticated designs, paper prototypes provide a great solution for generating initial feedback.

In his article criticizing the use of paper prototypes, Jake Knapp makes the point that when we show customers a paper prototype we’re inviting feedback, not reactions. What we found in our research however, was quite the opposite. In our sessions, participants voiced their expectations and understanding of what actions were possible at each stage, without us having to probe specifically for feedback. Sure we also received general comments on icon or colour preferences, but for the most part our users gave us insights into what they felt throughout the experience, in addition to what they thought.