This week, we’re looking at how we can use prototyping and usability testing to bring our ideas to life and assess their validity with users.

Prototyping allows us to quickly build on ideas generated in the ideation stage and observe how customers interact with them. Using a range of tools and techniques, we can test for usability issues early and avoid spending time developing concepts that don’t meet the expectations of our users.

This is step 3 in a 5-piece product design series.

  1. Understand
  2. Ideate
  3. Prototype & test
  4. Visual & motion design
  5. Measure impact

Step 3: Prototype & test

Prototype & test

At the end of the ideation stage, you should have an idea or two that you’ve decided to develop further. To ensure you stay focussed, it’s important to define the goals of your usability test:

  • What are you testing?
  • What questions do you want answered?
  • How do you define success and failure?
  • What are the distinct differences between different prototypes?

All of these questions will help you to define the goals of your test and work out the best approach.

Defining these goals will also help you to choose an appropriate tool to create your prototype. For high-level user journeys, you may find a paper prototype is sufficient, but for a more complex interaction, a higher-fidelity prototyping tool may be more suitable.

Prototyping tools

Paper & pens

Paper prototyping is a quick, creative, cost-effective technique, perfect for assessing high-level user journeys. For this, you’ll need a pen, paper (or device templates) and an assistant to manipulate the prototype as the user interacts with it.

Paper prototyping


The (free) POP app allows you to link the screens of your paper prototype with hotspots and test them on a mobile device. Simply add photos of each screen and link the screens together to create a more native, clickable experience.


The Invision tool, along with many other great features, allows you to create high-fidelity interactive prototypes that can be tested from the web app, mobile device or via a remote testing service powered by Lookback. You can even define gestures and transitions for a more realistic experience. Dropbox Sync also allows you to sync your design files directly to a prototype for quick, easy updates from your Mac.

Invision prototype


Principle provides the ability to define more complex gestures, interactions and transitions, allowing you to create a near-native experience with minimum effort. There are a number of online tutorials that can help get you started.

Usability testing

Observing the way your customers interact with your product provides you with invaluable insight into user behaviour. It allows you to prove or disprove hypothesis, validate your ideas and unearth usability issues early on.

Ways to test

Depending on the tool used to create your prototype, there are a variety of approaches you can take to conduct usability testing. In-house sessions allow face-to-face contact with users, provide invaluable insight and encourage empathy within the team.

Usability testing

There are also some great remote usability testing services such as WhatUsersDo and that allow your screened participants to follow a test script while recording their experience for you to watch back later.


Recruiting the right users is key to achieving realistic results from your tests. The ideal participants are customers who are currently engaged with your product on the platform you are testing on. If you are unable to do this, recruiting users of a similar demographic would be the next-best thing. You can advertise for participants on local classifieds or use a research agency to arrange your sessions.

If you use a remote usability testing service you will also be able to screen participants based on demographic, location and device/operating system usage.

Test script

Preparing a test script not only forms the basis for your session but also encourages focus on the goals. It’s important to state goals, hypothesis, session structure and approach methods as well as specific questions and guidelines for the moderator who is leading the session. It’s always worth running a pilot test so any script or technology issues will be highlighted prior to your participant's arrival.

For remote testing sessions, don’t forget to break out the participant questions into a separate document.

Moderating & recording

During the testing session, you will need two people: a moderator and a recorder. The moderator is responsible for keeping the session on-track and guiding the participant through the tasks and the recorder is responsible for recording notes, quotes and any usability observations.

Usability testing recording

If you have observers outside the testing room they can write key points onto sticky notes and add them to boards assigned to each test goal, ready for the conclusion session. It’s worth getting as many of the team along to observe as possible as seeing a user interact with your prototype firsthand can be a great learning experience for everyone involved.

Concluding results and defining next steps

By the end of the session, you will have gathered a number of useful insights on the usability and perceptions of your product. It’s important at this point to organise insights into each of the test goals and separate any additional insights for consideration. You'll notice some recurring issues, which can be grouped and summarised. Grading usability issues with a severity rating will help you to prioritise changes. You can also document additional insights to prioritise for future development.

Concluding usability testing results

Once your testing has finished it's important to document your findings for future use and share them with the rest of the team. A unified understanding of the insights will help to generate empathy for the customer and create a team focus.

Thanks to Caroline Smith, Lena Sarp , Rimas Albert and Robbin Staack for making prototyping and testing so fun and insightful.