Keep on testing! Keep on optimizing! Focus on your user!

Why usability matters and what you should do about it

If you want a great site, you’ve got to test. After you’ve worked on a site for even a few weeks, you can’t see it freshly anymore. You know too much. The only way to find out if it really works is to test it.
— Steve Krug

Usability is a crucial factor for a product. Most of the time, people use such terms in the scope of digital products, websites and apps. But did you know, that a bad usability can kill people? You might leave an online shop when you can’t finde the checkout button, but what would you do when you are a pilot and you can’t find the button to adjust the flaps? Or if you are a nurse and you accidentally turning off the respirator?

Most of you are more likely to deal with the first than with the second or third scenario. Lucky you!

Short recap — Usability and user experience

Usability — the ability to use a ^(product|app|website)$, defined by three criteria:

  • Effectivity: Can you reach the goal?
  • Efficiency: How easy/with which effort can you reach the goal
  • Satisfaction: How satisfying is it for you, when you reach your goal?

Your goal can be everything from buying shoes in an online shop, connecting and managing all your home products via some smart home applications, or: landing a plane without crashing it.

Usability ≠ User experience. User experience is more than Usability, Usability is a part of UX. It covers every phase of experiencing and using a ^(product|app|website)$, from evaluating alternatives to decision making to the actual use. UX describes, how you experience something, and not only how easy it was to use. Vice versa, when you can’t use something, how likely is it that you will have a positive experience?

User Experience — Put the user in the center of your product

So… how to achieve a good usability and create overwhelming user experiences?

I’ve written my master thesis on the wide topic of usability evaluation and optimization methods which help us making products (digital and physical ones) more usable (and more safe!) and joyful to use. One small part of my thesis was the the development of a reference framework to compare, classify and score common usability methods (empirical/expert based and those with user participation) to make it easier for you to choose the right ones to use in your next projects or to test your products.

Many books, articles and papers have been written and published on that topic, but there is a lack of a comprehensive view that can also be of practical use — trust me, I did much research and spend hours separating those buzzword sources (trying to sell you their view on usability and user experience) and those over-academic sources (all writing papers for other academics, but you get the feeling they never ever applied anything of their research in the field).

One page to describe them all

The first result of this reference framework is a one page briefing per usability method. Since you can classify every usability method with the same basic set of characteristics, you achieve comparability. This briefing covers the following parts:

General description of method:

  1. Goal of evaluation (what will be tested)?
  2. What kind of method (Analysis, experiment, observation, questionnaire)?
  3. Scope (formativ/summative)?
  4. Can it be combined with other methods?
  5. Where does it take place?
  6. Costs (Money, time, training)


  1. Do you need professional usability experts?
  2. If yes, how many?
  3. Do you need test subjects?
  4. If yes, how many?
  5. Do you need special technology (Hardware, software)?
  6. Do you need a test leader?


  1. Planning phase: Time effort?
  2. Planning phase: Technical effort?
  3. Test phase: What kind of prototypes/mockups can be tested?
  4. Test phase: Time effort?
  5. Test phase: Technical effort?
  6. Test analysis: Time effort?
  7. Test analysis: Technical effort?
  8. What are the results? (quantitative/qualitative, objective/subjective date)

After knowing the characteristics of different methods, you also need to know the strengths and weaknesses of each method. You don’t want to choose the one method that fits, but the one that fits the best.

Which to use when?

Usability testing and optimization is crucial in every phase of your conception and production. Once a product is finished (of you think it is), you still have to test, optimize and make your product stand out. You can use one of the following methods and techniques:

HE=Heuristic evaluation, CW=Cognitive Walkthrough, GL=Guidelines, UT (L)=Usability Testing (Lab), UT (R)=Usability Testing (Remote), ET=Eye tracking, MT=Mouse tracking, AB=A/B testing

Or you can use another of the 1,342 usability & UX methods out there — there is no holy grail to testing. With all the new possibilities (analytics, real-time monitoring, mobile testing) it is getting more complex every single day. What matters:

Keep on testing! Keep on optimizing! Focus on your user!

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