What is usability testing, and why is it so important?

The user experience design process focuses on creating products, systems, or services that provide meaningful and positive experiences for users. Engaging in a range of activities and techniques helps understand user needs and behaviors, leading to the development of enjoyable products.

The User Experience Honeycomb outlines seven essential user experience dimensions, as Peter Morville described, that contribute to a positive user experience. The first facet he describes is “useful,” stating that the core of a good product is to have a purpose and to fulfill a need. Right after that comes “usable,” meaning that after we make sure that we solve users’ problems, we need to address whether users can use the product.

Usability is a quality attribute of the user interface (UI) that refers to the ease with which users can interact with it. It’s a requirement for any successful product and the responsibility of us designers to guarantee it. This article explains why designers emphasize usability testing and how it benefits any product.

What is usability testing?

Usability testing evaluates how effectively a user can use an interface to achieve goals in a specific context. In a usability test, the moderator asks a participant to complete tasks while observing their behavior and listening to feedback. We record sessions, share results with the team, and provide actionable steps to improve usability.

When a user accesses an app, like a bank app, they typically aim to achieve a specific goal, such as checking their balance, paying rent, or depositing a check.
You can map those goals into smaller tasks that represent the necessary steps to achieve each goal. Observing users complete tasks helps evaluate an interface’s usability by measuring its effectiveness, efficiency, and satisfaction.

Effectiveness refers to the accuracy and completeness of the tasks. Was the user able to deposit the check? What issues did they encounter along the way? 

Efficiency refers to the effort the user needs to input to achieve results. Did they complete the task quickly? Did the user get sidetracked or stuck somewhere? 

Finally, satisfaction refers to the user’s emotional response and how satisfying it was to fulfill the task. This will give us a picture of the interface’s usability state and the issues to tackle. 

Why is it important?

Investing in good usability has become essential in today’s fast-paced digital landscape. Complicated interfaces that are time-consuming to learn and prone to errors can be a major deal breaker for many.

Let’s consider B2B applications, as an example, where poor usability can highly affect employee productivity and create big-scale problems. Moreover, usability tests are valuable for identifying issues that could impact user interaction with the product. They help us create superior user experiences while also saving valuable time and resources.

The key advantages of usability testing include:

• Detect issues early: One of the main outcomes of usability tests is to proactively identify potential issues. By observing the user interact with an early product version, we can uncover potential problems that can lead to unsatisfied users. Also, fixing them beforehand will allow us to guarantee a smoother and more enjoyable experience
• Inform the design: Designing an interface requires making many decisions, from the color palette to the navigation structure. Although designers study and implement several guidelines as part of their daily work, all users are different, and an interface that works for one particular context might not work for another. Usability testing allows us to validate design decisions and inform future ones to better align with user expectations. 
• Save money: Detecting issues early in the development process allows for timely resolution before they impact the final product. Moreover, this proactive approach minimizes the need for rework that may arise from late-stage discoveries, ultimately saving valuable time, resources, and development costs.
• Discover opportunities: Observing users interacting with the product can help to better understand the reasons why users use the product and in what context. Even if there are no critical errors with the interface we can discover how users feel about certain features and get actionable insights to drive iterative improvements.
• Gain competitive advantage: In a competitive market, businesses must look for ways to differentiate. When products offer similar features, a superior user experience can be a deciding factor and give the product a competitive edge. Furthermore, positive experiences also lead to better reviews and increased customer loyalty, contributing to a better market position.
• Learn more about users: Interviewing users is often part of a usability testing session. It helps contextualize users’ actions and understand why they might be doing things a certain way. Also, learning more about users’ motivations, needs, and pain points is incredibly valuable for creating empathy with the user and developing a user-centric mindset within the development team.

When to do usability testing?

Usability testing can be introduced in many stages of the development process; usually, the sooner, the better. Depending on the stage we are in, we can test different things:

• When redesigning an existing product, we can test the existing interface to find problems that should be fixed and good parts that should be kept or emphasized in the next version.
• At the beginning of a project, we can use sketches or wireframes to test different concepts or structural decisions like information architecture quickly. The sooner we start testing different ideas, the less effort is invested in the wrong path, and the chances of rework are reduced in the future.

• When the delivery milestone gets closer, we can test fully designed prototypes for more granular usability issues and fully evaluate the experience.

• After launching a product or a feature, we should continue to test our designs because there is always something that can be improved. We can also test more specific user types that we didn’t prioritize before and plan targeted optimizations for them.

Types of usability testing

Qualitative vs. quantitative

Qualitative and quantitative testing complement each other and play important roles in the design process. Depending on the product’s needs, we might benefit from one or the other or both.

• Qualitative testing focuses on gathering insights and in-depth feedback. This type of study is well suited for identifying the main problems in a design and informing design decisions. Furthermore, the data is gathered by doing observations and interviews and is suited for every stage of the development process.
• Quantitative testing, on the other hand, focuses on collecting numerical data, such as time, success rate, or satisfaction ratings. It’s usually done with complete designs and evaluates the usability of the interface.

Both types of studies can look quite similar as they both involve users performing tasks on an interface. However, the biggest difference is in the number of users needed and the strictness of the test conditions.

Qualitative testing primarily focuses on identifying issues. Research shows that as few as five users are sufficient to uncover the main problems. In contrast, quantitative studies involve a relatively large number of users (often more than 30), and the test conditions need to be well-defined and strictly controlled to protect the test from random events. 

In-person vs. remote

The choice will largely depend on the project’s context and the specific objectives we aim to test. In-person testing allows for close observations and fast follow-up questions and removes the technology barrier that might be an issue for some users. On the other hand, remote testing can be more practical since there is no need for the user or moderator to dislocate, but with a less controlled environment since external conditions might affect the test. Also, another characteristic of remote testing is that the moderator can either be present or not.

Moderated vs. unmoderated

Remote tests provide greater flexibility. Currently, a wide range of tools provide instructions to the user and record the interaction without the need for a moderator. This type of test will allow us to gather data more quickly and cheaply. The issue with unmoderated tests is that we might end up not understanding the full motives of why a user did something in a specific way and not getting many actionable insights. Some of the moderator’s responsibilities include making sure the test runs smoothly, clarifying any situation that arises during the test without interfering with the results, and incentivizing the user to think out loud – a crucial aspect for acquiring valuable insights

Final thoughts

Conducting simple usability studies can be ineffective. However, as the study scale and user sample size increase, expenses also rise.

Factors to consider when planning

Regardless of the test type, the following factors should be taken into consideration when planning:

• What are our testing objectives and anticipated outcomes from these sessions? There is a wide range of research methods, so we should evaluate if usability testing is the best method to retrieve the information we need. If so, which type will help us collect that data better?
• How critical it is for the product to conduct a particular test. The answer to this will highly depend on the current development phase and the size of the team. When time and resources are a constraint, we have to prioritize the features that will actively contribute to the success of the product. The more risky the feature is and the less clarity we have about it, the more we need to invest in research. 
• The type of users needed and how they will be recruited. The more specific the target users are, the harder it will be to find them. It’s crucial to plan time to find the right users. Alternatively, there are recruiting firms available that will find participants based on a specific set of characteristics. In that case, the budget needs to be considered.

• A budget for participant compensation. Depending on the type of users needed, we might need to offer monetary or non-monetary incentives, especially for working professionals.

• Time and resources to prepare, conduct, and analyze the tests. As a reference, small iterative tests can only take a couple of days in a sprint, but a more extensive test can take weeks until we have results. If there is no availability inside the team, many design companies provide usability testing as part of their services.

• Necessary tools and logistics. For on-site sessions, we need to consider location and transport; for remote sessions, a screen-sharing software. We also might need equipment or software to record and a research repository to document the collected insights.

Conclusion

When planned right, usability tests will allow teams to get cheap, recurrent feedback that will actively inform the development process. Observing users interacting with a product is the most effective and efficient way to uncover usability problems and provide insights to build successful products that people will enjoy using.