CX Insights

The Term Game: Usability Definitions

5 min read

When it comes to learning about the web, optimization, and usability, it often feels like we’re confronted with a whole bunch of buzzwords and acronyms without much context.

UX? UI? UCD? Want to know the difference once and for all without having to consult Google?

Well, you’ve come to the right place. We’ve put together a short usability dictionary of the terms we come across in our day-to-day scrolling. So grab a coffee, put your feet up, and get ready to learn.


According to the International Standards Organization (ISO 9241), Usability is the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency, and satisfaction in a specified context of use. In other words, good usability implies that users can easily use a product and by doing so, reach their goals quickly and without meeting friction. Some aspects of usability overlap with the user experience (UX) of a system, meaning good usability should also include a good user experience.

User Experience (UX)

UX is the subjective feeling a user gets when using a product, system, or service. User experiences are drawn from a user’s individual perception of different aspects of the experience such as appeal, information content, accessibility, credibility, relevance, ease of use, etc.

User Interface (UI)

The UI is the interface of any machine or system the end user interacts with. Through the user interface, the user operates the machine or system and receives feedback over success or failure of the given orders. In order to fulfill the requirements of good usability and user experience, a user interface needs to be usable, intuitive and, to a certain degree, fun to use.

usability abc

Usability Engineering

Usability engineering basically covers all aspects related to establishing usability. However, it’s not about the design of a product but about creating computer interfaces that allow users to effectively and efficiently accomplish their goals. Alongside this, usability engineering links the challenges claimed by the user with often inflexible organizational processes.

Human Computer Interaction (HCI)

As you might have guessed, HCI is all about people, computers, and interaction. Basically, it’s how people use computers. HCI looks at human usage of interactive computing systems from multiple perspectives including computer science, psychology, ergonomics, and sociology. The main objective is it to bring users and computer systems closer together so systems can be used more effectively.

Interaction Design

When we hear the term interaction design, we might be tempted to believe that it’s the actual design we encounter on a website. However, while a graphic designer comes up with the visual design, an interaction designer is responsible for the dialog between user and interface. Interaction design covers the conception and functionality of an interface which facilitates the communication between user and interactive system.

User Centered Design (UCD)

UCD describes the development process of any kind of product or user interface that has the end user as its main focus. UCD always starts with a thorough analysis of the needs, expectations, and limitations of the user. The design process is iterative and involves repetitive user testing to validate each step of the process.

usability definitions

Iterative Design

Iterative design describes a cyclic design process which is defined through repetitive user testing. Based on a first concept, a prototype is created. This prototype is tested to verify the concept. After analyzing the test results, the concept is refined and the design goes into its next iteration. This process is repeated until users find no more issues that need to be addressed.

Search Engine Optimization (SEO)

The Web offers endless opportunities to sell services, information, or products. However, in order to profit from these opportunities, it is essential to rank high in search engines like Google or Yahoo. Using SEO best practices to optimize your elements such as your website copy will increase the chance that your website is found and, in turn, drive traffic to it.

Conversion Rate

Conversion rate describes the number of users who engage in desired actions after visiting your website. These actions can be subliminal or direct requests made on the website. Depending on the services you offer, this can be a signup for an account, the purchase of a product, the request for further information, or anything else you want your users to do.

A/B Testing

A/B testing is a simple yet effective method for testing changes to a web page, and for determining how those changes affect conversion rate. Imagine you have two versions of your homepage: version A and version B. As visitors come to your homepage, you choose to display version A to 50% of your visitors; whilst showing the other 50% version B. Observing the visits to each version of the homepage combined with some quantitative and qualitative analysis will then show you which version performs best, and thus, should be implemented.

User Feedback

User feedback is the best way to get qualitative insights on your website or app, regardless of whether you’re running A/B tests or not. Use tools like Usabilla to prompt your visitors for either solicited or unsolicited feedback meaning you can make the most of your time by basing decisions and changes on real, contextual insights straight from the people who use your products most.

And there we have it. Any Usability terms you think we’ve missed? Let us know in the comments or shoot us a tweet @usabilla.


UX Fundamentals: The Concepts, Process and Proving the Value

Robyn Collinge
As Usabilla's Copywriter, Robyn brings nice words together - like peanut butter, napping, and Sunday brunch.