How to run usability testing of an interface

What is usability testing?

Usability testing — is a quality method of client experience research that suggests that users do typical tasks when interacting with sistem’s interface.

  • Automatic (the respondent fulfills tasks in special software) with moderator included (ux-researcher participates in the testing);
  • By degree of participation of the ux-researcher: moderated (ux-researcher talks to the respondent) and not moderated (ux-researcher only observes the respondent`s actions);
  • By respondent`s location: intramural, distant (with the using of programs for video conferencing) and field (observing the user in real time);
  • Depending on the goal: exploratory (testing comfortability of using the MPV), verificational (searching for usability problems in the existing service), comparative (comparing the interfaces of rival services)
  • Increasing of conversions’ percents in target action (buying a product, subscribing to a service);
  • Recession of rejections (the ratio of those who quit a page after the loading to the total number of visitors);
  • Increase of user’s productivity (number of targeted actions per unit of time);
  • Reduction of the excessions on supporting the product.

Algorithm of usability testing’s conduction
What are stakeholders

Stakeholders are people who are interested in your project. When you define who are stakeholders, you acknowledge their goals and how much they affect the project. In the large companies it is common that several subdivisions are involved in the development of the same product and it would be a mistake to not take into the account opinions of those who have influence on the product.

How to find aims and objectives of a research

It is necessary to talk to the stakeholders and figure out (even if the stakeholder is your supervisor) the goal of a research — is the final result on which the research is directed (to increase the conversion into the target action from 1% to 4%, for example).

How to find your target audience

Target audience is a group of people who are united by a quality that is a reason for having an ache or a need in the product.

  • User’s experience (they have the experience of using the product, don’t have any experience of using the product, have the experience of using a similar product);
  • Using the interface on a specific devise (smartphone with iOS or Android software);
  • Role in the company (for example, superviser, accountant or analyst);
    Work in a company of a certain scale (small, medium and large business).

Heuristic interface analysis

Heuristic analysis — is an expert rating method when the interface is being analyzed by an expert to see if it matches specific principles that are called heuristics.

Formation of hypotheses

Hypothesis — is a valuable business assumption which needs to be confirmed or refuted.

  • Try to guess the client“s actions with the interface or ask 1 or 2 friends to do that;
  • Analyze the interface using the heuristics;
  • From quantitative metrics of a product, for example, CSI or NPS;
  • From complaints and reviews (for an existing product).
  • Short;
  • Binary (can be confirmed or refuted);
  • Consists a specific description of the user’s expected actions.
  • To form the opening questions before the testing
  • To turn client’s way in the interface into logical steps
  • To write client“s tasks on each step
  • Add questions after the task
  • Questions that help to confirm or refute hypotheses;
  • Questions that show the client“s logic if deviate the from the way that was planned for them;
  • Questions that show the additional needs.

Recruiting the users

First of all you need to reach an agreement with the stakeholders on the subject of the number of the respondents who provide the research“s representativeness.


Moderated usability testing of the interface of a medium difficulty usually takes 45 minutes ± 15 minutes depending on a client“s activity. In my experience, if you run a research for more than an hour, the respondent gets tired, their concentration worsens and test results get distorted.

  • Getting acquainted — we need to introduce ourselves and talk about how the meeting is going to pass in order to deprive the client of any fears. On this step we need to establish trust in the relationship with the respondent.
  • General questions on the researched matter — we need to speak about the researched matter in general: how the client solves their need, which product they use, how the client characterizes the existing products
  • Testing of the prototype
  • Summing up the meeting — we need to say the client“s wishes in order to figure out if we understood them correctly, and then we need to thank the client for the meeting
  • Immerses: gives tasks, motivates the users to comment their actions while working with the prototype
  • Asks: clarifies the reasons of the users“s actions during the fulfillment of a task
  • Watches: keeps track of and fixates how the user works with the service
  • Asking «closed» questions that can only be responded to by «Yes» or «No». Example: Did you understand everything on this page? Because we are speaking about moderated usability testing, you have an opportunity to ask «open» questions and detect the user“s motivation. Example of an open question: «Why did you choose this package of services?»
  • Talking more than the respondent. We explore the client’s experience, not the researcher’s. Researcher“s function is to ask questions and clarify why the client did what they did.
  • Asking questions with a hint, for example: «You use the product rarely because it’s expensive or you just don“t see any benefit?»
  • Arguing with the client or trying to convince them. If clients make mistakes, then our goal is to find out why it happens. And then to solve the problem by changing the interface. If you convince the client that you are right, then the problem won“t be solved.
  • Using professional vocabulary. Not all clients might know the names of the interface elements. For example, when speaking about one of the types of navigation in the «breadcrumbs» network, some people can understand a word literally and get confused.
  • list of steps with signs «made it/ didn’t make it/ made it but had some difficulties»
  • List of difficulties that the client had during the testing
  • Hypotheses with the signs «confirmed/ not confirmed»
  • Client’s expectations and wishes if the client said them

Testing results analysis

The perfect option is to analyze the direct speech of the clients. The first option: transmitting audio into text by hand but this is labor-intensive. For automatisation you can search for services that can transcribe the text, the list of these services will vary depending on the language of the speaker.

  • We state the problems that were detected in testing. A good description of a problem consists of two parts: Description of the respondent’s behavior and description of the design’s peculiarities to which some difficulties are connected. Example: the respondents don“t press the button with settings because it’s grey and looks inactive in users’ perception.
  • Pinpoint a problem`s frequency. Metrics help to understand what problems need to be corrected in the first place.
  • Define the problem`s criticality. We can divide all problems on: critical are those that don’t let the user to fulfill a task or fulfills it incorrectly; of medium criticality — the user spends much time and strength and their satisfaction with the service decreases; problems of low criticality don“t affect the success of fulfilling a task but decrease the satisfaction from the service.

Quantitative metrix

Usability testing could be supplemented with the quantitative metrics. Metrics need to be discussed in another article that’s why we will mention only the main features.

  • Objective:
    - Time for accomplishing the task
    - Task Completing Success rate
    - Mistakes frequency
  • Subjective:
    - System Usability Scale (SUS)
    - Single Ease Question (SEQ)
    - Usability Metric for User Experience (UMUX)
    - Customer Satisfaction Score (CSAT)
  • Prove — numbers are used as a proof for decision makers, those who are used to numbers;
  • Put an emphasis — number illustrate the problems better;
  • Show the dynamics — if you systematically measure the indicators, you can track the efficiency of changes in the interface.

Benefits of improvement

It is often difficult to understand how to divide the change of the income that comes from usability testing or from the other company’s activities such as marketing or sales. That’s why it’s not always possible to define the income and ROI.

  • Increase of the product income (for example, increase of purchase conversions);
  • Reduced product costs (for example reduced number of calls to the call center).


Deloitte company published a text saying that customer-centric companies are 60% more profitable than the others. Use the instruments of working with the clients’ experience (usability testing included) to make your client happy and be successful in business.



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