Usability testing: why you should do it?

Prueba de usabilidad | Pruebas UX | Tests de usabilidad
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Usability testing is crucial before launching a digital product. Would you launch a car into the market without verifying that everything works first? And as a consumer, would you buy it without trying it out first? Almost certainly, the answer is no. The same applies to a digital environment, whether it’s a website, an app, or a prototype. Developing these kinds of digital products involves a chain of work that impacts many aspects, including programmers and developers, designers, product managers, marketing, content, and more. Therefore, conducting a user experience test to detect issues, solve problems, and avoid future changes before the project’s launch is crucial for its success, as well as for reducing unnecessary costs and efforts.

The main protagonist of the usability test is the user and their interaction behavior within a specific digital environment. This user may encounter difficulties in performing specific tasks, such as not finding how to filter the type of car they want to rent, subscribing to a newsletter on an e-commerce site, or facing issues during the registration process on their online banking website. When these «minor problems» arise, it’s essential to address them promptly through usability testing to prevent more significant issues.

To begin, think about the goals you want to achieve with this type of test (take a few seconds to think). Now, let’s apply the most appropriate research techniques from two different perspectives: a more quantitative and a more qualitative approach. We’ll explain them below.

Usability Testing: Qualitative Approach

If your primary research objective is to evaluate the overall user experience on your website or app, detect problems, and identify potential improvements, then the user experience test or usability test should be approached from a more qualitative perspective. This type of study has its characteristics, limitations, such as sample size, techniques used, and the information obtained.

Let’s start with the sample. For these types of research, it’s recommended to have a small sample with few users due to the depth of each individual study, budget constraints, and the time required for extensive research. The exact number depends on each specific case and study, but as a general guideline, it’s recommended to use samples of around 10 individuals, and in any case, fewer than 20 subjects. In this regard, the results do not have statistical significance and cannot be extrapolated to the entire population. Still, they provide valuable insights into the issues users encounter while navigating. These issues or errors often go unnoticed by the individuals who design and execute the project under investigation, as they are somewhat biased by the development process.

Regarding techniques and results, this type of study primarily relies on individual interviews or focus groups. Each session, lasting approximately one hour, involves tasks such as card sorting and tree testing to evaluate the understanding of menus and information architecture on the website, heatmap analysis to identify mouse movements, click sequences and scrolling, along with session recordings to understand user flow and behavior.

Due to the methodology used, a substantial amount of subjective information is obtained for analysis. This means that the researcher must pay close attention to the reactions, gestures, or comments made by the test participant to accurately convey their behavior and issues encountered during the tasks.

Usability Testing: Quantitative Approach

If your usability study goals are more related to business and conversion, and you aim to obtain statistically representative global patterns of usage, then the most suitable methodology is quantitative usability testing.

In this case, the goal is not to delve deeply into the responses of a few «chosen» individuals but to obtain statistically valid behavioral trends from a larger sample. As with qualitative studies, there is no ideal and exact sample size, but it is recommended to have a larger sample with statistical significance. Typically, a sample size of over 250 is recommended, and an optimal sample size could be around 400 users.

Quantitative usability tests work well with online market studies, which can target as broad a sample as desired with specific segmentation. This allows for the design of A/B tests to determine which of the two given options works better for users, first impression tests, concept tests, copy and CTA choices, and any functional analysis proposing tasks to measure the effectiveness and efficiency of the analyzed environment.

Choosing the Right Methodology for Your Usability Test

Both methodologies are not mutually exclusive, and the ideal scenario is that they are complementary. Why? Because quantitative usability testing can mathematically validate the analysis and conclusions obtained from qualitative testing. In other words, it can statistically confirm which option works better concerning the identified issues and provide the market with a product that has the highest usability ratings and the best chance of success.

At We are testers, we specialize in both types of usability tests and have the capability to adapt different test types to each specific case study. The application of these methodologies has helped brands such as Desigual, Axa, or Europcar identify issues and propose improvements in their brand’s new application, understand why various functionalities work or don’t work on their websites, and analyze the hiring process to improve conversions through their site.

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Update date 22 December, 2023

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