Web usability guide

9 min read Optimal Workshop

There’s no doubt usability is a key element of all great user experiences, how do we apply and test usability principles for a website? This article looks at usability principles in web design, how to test it, practical tips for success and a look at our remote testing tool, Treejack.

A definition of usability for websites

Web usability is defined as the extent to which a website can be used to achieve a specific task or goal by a user. It refers to the quality of the user experience and can be broken down into five key usability principles:

  • Ease of use: How easy is the website to use? How easily are users able to complete their goals and tasks? How much effort is required from the user?
  • Learnability: How easily are users able to complete their goals and tasks the first time they use the website?
  • Efficiency: How quickly can users perform tasks while using your website?
  • User satisfaction: How satisfied are users with the experience the website provides? Is the experience a pleasant one?
  • Impact of errors: Are users making errors when using the website and if so, how serious are the consequences of those errors? Is the design forgiving enough make it easy for errors to be corrected?

Why is web usability important?

Aside from the obvious desire to improve the experience for the people who use our websites, web usability is crucial to your website’s survival. If your website is difficult to use, people will simply go somewhere else. In the cases where users do not have the option to go somewhere else, for example government services, poor web usability can lead to serious issues. How do we know if our website is well-designed? We test it with users.

Testing usability: What are the common methods?

There are many ways to evaluate web usability and here are the common methods:

  • Moderated usability testing: Moderated usability testing refers to testing that is conducted in-person with a participant. You might do this in a specialised usability testing lab or perhaps in the user’s contextual environment such as their home or place of business. This method allows you to test just about anything from a low fidelity paper prototype all the way up to an interactive high fidelity prototype that closely resembles the end product.
  • Moderated remote usability testing: Moderated remote usability testing is very similar to the previous method but with one key difference- the facilitator and the participant/s are not in the same location. The session is still a moderated two-way conversation just over skype or via a webinar platform instead of in person. This method is particularly useful if you are short on time or unable to travel to where your users are located, e.g. overseas.
  • Unmoderated remote usability testing: As the name suggests, unmoderated remote usability testing is conducted without a facilitator present. This is usually done online and provides the flexibility for your participants to complete the activity at a time that suits them. There are several remote testing tools available ( including our suite of tools ) and once a study is launched these tools take care of themselves collating the results for you and surfacing key findings using powerful visual aids.
  • Guerilla testing: Guerilla testing is a powerful, quick and low cost way of obtaining user feedback on the usability of your website. Usually conducted in public spaces with large amounts of foot traffic, guerilla testing gets its name from its ‘in the wild’ nature. It is a scaled back usability testing method that usually only involves a few minutes for each test but allows you to reach large amounts of people and has very few costs associated with it.
  • Heuristic evaluation: A heuristic evaluation is conducted by usability experts to assess a website against recognized usability standards and rules of thumb (heuristics). This method evaluates usability without involving the user and works best when done in conjunction with other usability testing methods eg Moderated usability testing to ensure the voice of the user is heard during the design process.
  • Tree testing: Also known as a reverse card sort, tree testing is used to evaluate the findability of information on a website. This method allows you to work backwards through your information architecture and test that thinking against real world scenarios with users.
  • First click testing: Research has found that 87% of users who start out on the right path from the very first click will be able to successfully complete their task while less than half ( 46%) who start down the wrong path will succeed. First click testing is used to evaluate how well a website is supporting users and also provides insights into design elements that are being noticed and those that are being ignored.
  • Hallway testing: Hallway testing is a usability testing method used to gain insights from anyone nearby who is unfamiliar with your project. These might be your friends, family or the people who work in another department down the hall from you. Similar to guerilla testing but less ‘wild’. This method works best at picking up issues early in the design process before moving on to testing a more refined product with your intended audience.

Online usability testing tool: Treejack

Treejack is a remote usability testing tool that uses tree testing to help you discover exactly where your users are getting lost in the structure of your website. Treejack uses a simplified text-based version of your website structure removing distractions such as navigation and visual design allowing you to test the design from its most basic level. Like any other tree test, it uses task based scenarios and includes the opportunity to ask participants pre and post study questions that can be used to gain further insights.

Treejack is a useful tool for testing those five key usability principles mentioned earlier with powerful inbuilt features that do most of the heavy lifting for you. Treejack records and presents the following for each task:

  • complete details of the pathways followed by each participant
  • the time taken to complete each task
  • first click data
  • the directness of each result
  • visibility on when and where participants skipped a task

Participant paths data in Treejack

The level of detail recorded on the pathways followed by your participants makes it easy for you to determine the ease of use, learnability, efficiency and impact of errors of your website. The time taken to complete each task and the directness of each result also provide insights in relation to those four principles and user satisfaction can be measured through the results to your pre and post survey questions.The first click data brings in the added benefits of first click testing and knowing when and where your participants gave up and moved on can help you identify any issues.

Another thing Treejack does well is the way it brings all data for each task together into one comprehensive overview that tells you everything you need to know at a glance.

Treejack’s Task overview- all the key information in one place

In addition to this, Treejack also generates comprehensive pathway maps called pietrees. Each junction in the pathway is a piechart showing a statistical breakdown of participant activity at that point in the site structure including details about: how many were on the right track, how many were following the incorrect path and how many turned around and went back. These beautiful diagrams tell the story of your usability testing and are useful for communicating the results to your stakeholders.

Pietree diagram

Usability testing tips

Here are seven practical usability testing tips to get you started:

  • Test early and often: Usability testing isn’t something that only happens at the end of the project. Start your testing as soon as possible and iterate your design based on findings. There are so many different ways to test an idea with users and you have the flexibility to scale it back to suit your needs.
  • Try testing with paper prototypes: Just like there are many usability testing methods, there are also several ways to present your designs to your participant during testing. Fully functioning high fidelity prototypes are amazing but they’re not always feasible (especially if you followed the previous tip of test early and often). Paper prototypes work well for usability testing because your participant can draw on them and their own ideas- they’re also more likely to feel comfortable providing feedback on work that is less resolved! You could also use paper prototypes to form the basis for collaborative design sessions with your users by showing them your idea and asking them to redesign or design the next page/screen.
  • Run a benchmarking round of testing: Test the current state of the design to understand how your users feel about it. This is especially useful if you are planning to redesign an existing product or service and will save you time in the problem identification stages.
  • Bring stakeholders and clients into the testing process: Hearing how a product or service is performing direct from a user can be quite a powerful experience for a stakeholder or client. If you are running your usability testing in a lab with an observation room, invite them to attend as observers and also include them in your post session debriefs. They’ll gain feedback straight from the source and you’ll gain an extra pair of eyes and ears in the observation room. If you’re not using a lab or doing a different type of testing, try to find ways to include them as observers in some way. Also, don’t forget to remind them that as observers they will need to stay silent for the entire session beyond introducing themselves so as not to influence the participant – unless you’ve allocated time for questions.
  • Make the most of available resources: Given all the usability testing options out there, there’s really no excuse for not testing a design with users. Whether it’s time, money, human resources or all of the above making it difficult for you, there’s always something you can do. Think creatively about ways to engage users in the process and consider combining elements of different methods or scaling down to something like hallway testing or guerilla testing. It is far better to have a less than perfect testing method than to not test at all.
  • Never analyse your findings alone: Always analyse your usability testing results as a team or with at least one other person. Making sense of the results can be quite a big task and it is easy to miss or forget key insights. Bring the team together and affinity diagram your observations and notes after each usability testing session to ensure everything is captured. You could also use Reframer to record your observations live during each session because it does most of the analysis work for you by surfacing common themes and patterns as they emerge. Your whole team can use it too saving you time.
  • Engage your stakeholders by presenting your findings in creative ways: No one reads thirty page reports anymore. Help your stakeholders and clients feel engaged and included in the process by delivering the usability testing results in an easily digestible format that has a lasting impact. You might create an A4 size one page summary, or maybe an A0 size wall poster to tell everyone in the office the story of your usability testing or you could create a short video with snippets taken from your usability testing sessions (with participant permission of course) to communicate your findings. Remember you’re also providing an experience for your clients and stakeholders so make sure your results are as usable as what you just tested.