Design thinking usability tests

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Good usability is essential for a successful user experience. In this blog I will talk about how usability can be ideally embedded in a design thinking process - evaluated in the form of usability tests - and how the user experience can be optimized.


Good usability is essential for a successful user experience. In this blog I will talk about how usability can be ideally embedded in a design thinking process - evaluated in the form of usability tests - and how the user experience can be optimized.

Do you know the feeling when you open a new application on desktop and feel completely lost? Why does this happen especially in a business environment and why is it that apps on smartphones can often be operated intuitively and feel so familiar when used unlike desktop applications?

Often, the reason why some applications are easy to use - whether on desktop or smartphone - is a previously carried out evaluation of the usability and the user experience (UX).

Usability and user experience - that is the same thing, isn't it?

In common parlance, the terms usability and user experience are mostly used synonymously - but appearances are deceptive.

According to ISO standard 9241-11: 2018, usability is defined as "the extent to which a product, system or service can be used by certain users in a certain application context in order to achieve certain goals effectively, efficiently and satisfactorily." This definition is a bit bulky, but it can be simplified as follows: good usability ensures smooth use, effective, efficient and satisfactory achievement of the desired goals while using a digital product or system.

An important indicator for assessing usability is compliance with and application of the seven so-called "interaction principles" according to the guideline for design of user interfaces (ISO 9241-110: 2020, Ergonomics of human-system interaction — Part 110: Interaction principles):

  1. Suitability for the user’s tasks
  2. Self-descriptiveness
  3. Conformity with user expectations
  4. Learnability
  5. Controllability
  6. Robustness against usage errors
  7. User engagement

Adhering to these principles ensures good (and noticeable) usability for digital applications.

But was there something else? Oh yes, user experience!

Here, too, there is a clear definition (ISO 9241-110: 2020) that draws UX as a bracket around “all aspects of a user's experience when interacting with a product, service, environment or facility”. Compared to usability, the focus here is even more on the user. His experiences, all perceptions, and reactions that arise before, during and after the interaction with a product or service are of great interest - especially for the UX designer. This has the task of not only ensuring the achievement of goals (see usability), but also to address the user on an emotional level and to generate positive feelings in the entire process of experiencing (before, during and after use). Ideally, the customer is already looking forward to using an application in advance, while using it, he can hardly put the smartphone down and then he is satisfied with what has been achieved with the help of the application. Ultimately, he also looks forward to future use of the application - this is a very positive effect, especially in the business environment!

UX is thus the all-encompassing approach when considering a product or service, usability is only a sub-area of ​​it that primarily comes into play when it is used. In digital applications, usability is primarily relevant in ​​the UI (User Interface). Now we have come back to the initial questions that I asked in the beginning of this article. The terms have been defined, but how can good usability be achieved? I will go into detail in the next section.

The customer is king…

... and in this case the king is the user. When designing and developing digital applications, the target user must be the focus from the very beginning. His wishes must be taken into account in the context of the “human-centered design process”. However, that doesn't mean that every wish should be implemented (maybe you know the Simpsons episode where Homer designs a car?) - this usually leads to disastrous results and / or projects that get out of hand in terms of costs.The Empathy MapEmpathy_map


Often this is due to the fact that users cannot estimate which technical implications the implementation of requirements entails and how relevant the desired functions are for the entirety of all users. In addition, the utterances of a user (say) do not always correspond to what they really do (do), think (think) or feel (feel) - this is exactly one of the core tasks of the UX Designer.

Embedding in the design thinking process

In my experience, the best results can be achieved with a guided and highly iterative design thinking process. Depending on the characteristics used, this consists of a total of six or more phases, between which you can switch depending on the situation and the result.

The design thinking process

The design thinking process consists of 6 phases:

  • Understanding (Scoping) Goal: Generating a common understanding of the problem
  • Observe (360 ° research) Goal: Understand the needs of users / customers
  • Define perspective (synthesis) Goal: Collect and condense knowledge
  • Finding ideas (ideation) Goal: Collecting and evaluating solution ideas
  • Developing prototypes (prototyping) Goal: Modelling solution ideas as prototypes
  • Testing (validation) Goal: Obtain user feedback

The phases that usually follow the core process are:

  • Developing (development)
  • Testing (testing)
  • Implement (implementation)

A team consisting of people with specialist and generalist knowledge (also known as a “T-shaped team”) should be put together to determine the needs of the future users, to specifically define the problems and ultimately to solve them in a targeted manner. A cost-benefit analysis in the sense of “What is feasible at what price?” Is always important. The resulting product should be tested regularly with the users for usability, which avoids the development of applications “in an ivory tower”.

Usability tests - what is the best way to proceed?

Usability tests are one of the supreme disciplines of a UX designer and show how users deal with applications designed for them in everyday life. I recommend that usability tests be carried out continuously throughout the entire development cycle - in this way, possible irritations for users, obstacles and problems when using the application can be identified and remedied at an early stage. As is so often the case here, the earlier you start, the better (and more cost-effectively) gaps can be closed and mistakes corrected. And the satisfied users will thank you in retrospect with increased productivity.

Usability tests can be differentiated based on the following criteria:

  1. Place of execution
  • in the laboratory (suitable room required)
  • in the field (on site at the user)
  1. Type of implementation
  • personal (more empathic)
  • distant (cheaper, also possible remotely)
  1. Type of moderation
  • moderated (deeper insights, possibility of inquiries)
  • unmoderated (automatable, cheaper, no demand possible)

How does a usability test actually work? Several individuals (5-10 test participants are recommended) with an identified shared user profile are observed using an application and, in the meantime, questioned by a trained interviewer. Various typical usage scenarios (e.g. cross-device, i.e. on the desktop and mobile) should be run through and realistic tasks should be processed. The interviewer guides the user through the application using a prepared interview guide. In addition, at least one recorder and, if necessary, other observers should follow the test separately (via video connection or, if available, in the next room via one-way mirror). The interviewer uses the Thinking Aloud Method, in which the user describes his approach orally, parallel to the processing of the test items, and expresses his thoughts aloud. Even subjective (and often very spontaneous) impressions made by the user give important input and should definitely be included.

In my experience, the correct use of thinking aloud, comprehensive observation of the test participants and accurate recording of the interviews are the decisive keys to the best findings (identified findings from the tests). After the tests have been carried out, these should be consolidated in the team and analysed with regard to the violated principles of interaction (according to ISO 9241-110: 2020, see above) and their severity.

In conclusion, every usability test is better than none, don't leave your users out in the rain with half-baked applications! If you have any questions or need support in the planning and implementation of usability tests (or design thinking workshops), please do not hesitate to contact us.