Methods and Types of Usability Testing
User Experience testing is getting more and more popular. We can choose from testing design mockups, layouts, websites, forms and many others. But the most important element is the choice of the right method, which is the first step to success
The choice of usability testing method depends on you – the result you want to achieve, your aims and the stage of implementation of your product. One thing is sure – you should test! So – let’s begin!
Individual In-depth Interviews
Also known as IDIs. These are one-on-one interviews conducted by the moderator. The interview is conducted on the basis of a prepared scenario which includes bullet points for the conversation or includes a detailed set of questions that we’re searching the answer to. The moderator focuses on asking open-ended questions and extending with additional questions to get to know interviewee’s behaviour better. One interview takes around 1-1,5h.
Uncover users’ attitudes, emotions and motivations. The use of projection methods allows to understand attitudes which were not directly revealed by users. A focus group test is a moderated discussion (facilitated by the previously prepared scenario with bullet points). The study aims at engaging participants in a discussion to confront their opinions. Typical focus group discussion involves 6-8 participants. It takes place in a room equipped in a two-way mirror, the whole session is also recorded.
- There are different variants to the typical focus group study:
- Mini-groups- smaller number of participants which gives each participant more time to talk and makes them more engaged. It enables going more deeply into the subject
- Conflict groups- group is divided into two subgroups with antagonistic views
- Creative groups- the aim of participants is to search for new, innovative and creative solutions
Method which is incredibly helpful at the stage of creating the site and later on while optimising the information architecture. In a card sorting session, participants organise topics into categories. The main aim here is to establish how users perceive the hierarchy of elements. The study should involve not less than 5 participants, the best number of participants is 15. One card sorting session should involve 30-40 cards (using more cards can be difficult to participants for purely cognitive reasons)
- There are 3 types of card sorting:
- Open sort– users receive prepared cards, organise them in groups and name each group they created. This method is very useful while creating new websites or applications.
Participants are asked to organise topics from content within a tested website into groups that make sense to them and then name each group they created in a way that they feel accurately describes the content. Open card sort shows how users group content and the terms or labels they give to each category.
- Closed or tree sort – main categories used in the study are pre-defined and cannot be changed. This method works best when you’re adding new content to the already existing website.
Participants are asked to sort topics from content within your website into pre-defined categories. A closed card sort works best when you are working with a pre-defined set of categories, and you want to learn how users sort content items into each category.
- Free list – participants create and name groups of cards and organise content within the categories they created themselves. This method is useful at the very early stages of designing a website structure.
You can also find its variation, the so called “hybrid list”.
The hybrid list is the combination of open and closed sorting. Participants to the study start with organising website content into pre-defined categories (closed sort). However, if they find that the pre-defined categories are not suitable for their needs, they can create their own categories (open sort).
More info you can find in our text – Card sorting – tips and tricks.
Method used to verify first interfaces. It enables the iterative product development cycle. Paper prototyping method uses paper models to simulate an interface which is evaluated by a user – the user points to elements he or she would click while searching for a given information while the moderator is switching between drawings of elements. The study facilitates discovering functional errors in a system without focusing on the layout of a product. It is also pretty time-consuming to prepare.
The product is evaluated by the UX expert (preferably with a few years of experience). The expert points out potential issues with the product and provides a general usability assessment.
- There are several expert review methods:
- Heuristic evaluation – a product’s interface is reviewed and compared against heuristics – accepted usability principles.
- Cognitive walkthrough – an expert plays a part of a user who is performing key tasks at a website (around 3-5 scenarios). The aim of the study is to connect a point of view of a user with the expert knowledge.
- Checklist – using checklists describing product’s operational model. The result of the analysis is the number of points or percentage scored. Sometimes next to enumerating errors the analysis will include many additional remarks e.g. recommended changes, description of good practices used by the competition.
Tracing users’ gazes with the use of the special device called eye-tracker. Products analysed with the use of this method are graphic designs, operating websites, marketing materials. The study should involve at least 7 participants.
Usability lab testing
Users follow pre-defined scenarios. Testing session takes place in a room divided into two parts by a two-way mirror – moderator with a participant of the study are in one part of the room while observers are in the second part. Usually during a session respondents’ desktops and facial expressions are recorded. This type of testing is used to discover functional issues in a product. It can also be used to test layouts and competitors’ websites. The test is often followed by an in-depth interview which takes place after completion of each task or by the end, to summarise the session. Typical usability lab testing involves 5-8 participants.
Remote usability testing
Online user research (without physical contact with participants of the test). Users’ behaviours are observed and analysed while they complete tasks at the website. The main advantage of this method is that users work in their natural environment – at home or at work. It is also time and cost-effective.
We can differentiate two types of remote usability testing:
- Moderated- enables direct interaction with users online or observing users while they complete tasks for a test. It is closer to lab testing.
- Un-moderated- participants independently complete testing without interaction with the test moderator. Participants complete tasks online and their results are available in an application/system later on. Numerous parameters are measured during the test e.g.. information on success or failure, time of implementation of a task, number of visited subpages. Also, desktop and facial expressions of users are recorded during the testing session.
Research method determining which of two alternatives for a website is better. The test can use versions differing in one or in several aspects. The test should involve at least 50 participants per one site version.
Used to follow users’ activity at websites. Participants’ clicks are measured up to a pixel (taking resolution, size of a browser window, location of a click into account). This method allows to evaluate the effectiveness of the linking structure of a website (where users click most often, which areas are regarded as clickable while they are not hyperlinks etc).