ABC of Usability

Usability Geek Logo The Usability ABC is a collection of Usability and User Experience (UX) definitions. It is a joint collaboration between Usabilla and UsabilityGeek. UsabilityGeek is a usability and user experience blog, which is owned and managed by Justin Mifsud, a user experience consultant.


A/B Testing
A/B testing is an extremely simple, yet effective, method for testing changes to a web page, and for determining how those changes affect the conversion rate An easy way of looking into it is as follows: 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.

Through observing these visits to each version of the homepage, a little bit of analysis (usually using analytics software) should show you the performance rates for each version; and thus the most successful option.

A/B Testing increases in usefulness the more hits site has, due to the increased amount of data received. Even if the tiniest of changes increases conversion by 1% over a pool of 500,000 visitors, it is worth doing. Google is well known for using this method extensively.

The accessibility of a website describes how well users with limitations can access it. These limitations can be technical, such as a slow Internet connection, or an outdated operating system. They can also be physical, like blindness, or for example a handicap that makes it impossible for users to operate a mouse. An accessible website offers solutions for these limitations, like a simple HTML version that does not require special browser plug-ins, low resolution images to ensure a short loading time, screen reader optimization, or the compatibility with alternative input devices.
Active informed consent
Active informed consent means that participants have actively decided to participate in a study. Usually participants receive a consent form, which they are asked to sign and return to the researcher. Active consent is only possible if participants are not under age. Active informed consent should for example be asked if the research is expected to have any personal, or long term impact on the participant, or if the researcher intends to publish any test material.
Affinity Diagram
An affinity diagram is a creative technique that enables the grouping of large amounts of data such as ideas, opinions and issues into related concepts. Such a diagram can be particularly useful in order to establish relationships between ideas generated by a brainstorming session. Typical implementation is carried out by writing ideas on pieces of paper, cards or stickers and then physically placing closely related concepts close to each-other. Such information is then steadily structured from the bottom up to create categories that describe related ideas.

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Brainstorming describes a creative process to generate ideas around a defined topic. You can brainstorm alone or in a group. Brainstorming in a group is handy because several people are likely to have more ideas than you have on your own. Besides, in a group, brainstorming can help to match up ideas about a certain topic and put everyone into the same perspective.
Breadcrumbs are a special form of navigation, which is sometimes offered on a website. Breadcrumbs help users orientate within a website by indicating their current location. They usually start at the home page and then list step by step the different web pages the user has visited before getting to the current page. Breadcrumbs are usually interactive and can be used to go back to any of the pages visited between the home and the current page.

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Card Sorting
Card sorting is a quick, inexpensive, simple, yet effective UX technique that enables users to define the structure, workflows, navigation paths and possible taxonomies of a system such as a website. This effectively provides a valuable contribution towards the information design process by shedding a light on the users’ mental models. Typically, users are provided with a set on cards containing the terms and they are expected to organize them into groupings that make sense to them. The results of these groupings, including the names given to them by the users are then analyzed by the UX specialist in order to observe patterns.
Chromostereopsis is a visual phenomenon related to our perception of colour, and how they eye and in turn our brain interprets it. Wikipedia defines it as, “”a visual illusion whereby the impression of depth is perceived in two-dimensional color images”. Through clever use of colour, we can trick our brain into creating depth where there is none. We can take advantage of this trick in visual design to help enhance certain aspects.
Closed question
In an interview or a survey, you can ask different kind of questions. One of them are closed questions. Closed questions are answered by choosing from predefined answers. These answers can for example be a simple yes or no, or a selection of several answer categories. Closed questions only give you a range of defined answers, which makes them quite easy to analyze. With closed questions, you get mostly quantitative data.
Conversion rate
Conversion rate describes the number of users who engaged 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.

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Debriefing describes the last phase of a user test, usually in form of a concluding conversation or in written words. During the debriefing, participants are given sufficient information about the purpose and set up of the study to avoid psychological damage or possible after-effects. Also misleading information that was given during an experiment, should be corrected. It should be one of your main concerns to make sure you don’t harm your participants in any way.
Desirability is a phenomenon that occurs in usability research when users give answers that are socially desirable instead of truthful. Users tend to form their answers in a way that is approved by others. This behavior can seriously influence your test results because participants might either weaken a negative aspect or qualify positive aspects. In groups, desirability can lead to consensus and therefore homogeneous results. To avoid desirability, make sure all participants feel confident to speak the truth.
Drop-down List
Drop downs are a commonly found user interface element. Found everywhere from Operating Systems to the internet, they serve the great purpose of using minimal screen real estate when not in use. Initially concealing their contents, when the user interacts with the drop down, the list is revealed. This is useful for hiding rarely used functions, keeping elements organised and for saving space. A key weapon in the UI designers arsenal.

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Engaged Time
Engaged Time tracks the length of time each user spends on a specific page. From this we can calculate an overall average of the time spent by all users. With this information we can understand if users are actually engaging with our content – not just simply browsing over it and going home. An engaged user is far more likely to connect with the brand in question. They are invaluable users, likelier to return for more than one fleeting visit.
Just as usability studies study the interactions between a person and technology; ethnography studies the interactions between a person, and other people and their environments. With little hypothesis, ethnography largely a case of observing people’s interactions and journeys through their environment. A qualitative form of research, aimed at exploring and representing these cultural phenomenon on paper.

Ethnography allows us to better understand our users, before they are users. It allows us to understand how their cultural habits will shape and affect their experience. Once we understand how a person or cultural group will [instinctively] interact with their environment, it allows us to design with this interactions in mind – to better design around our users, essentially forming the basis for User Centered Design (UCD).

Eye-tracking is a technique used in user testing to follow and capture people’s eye movement. There are both fast installed and portable eye-tracking devices that can be used to observe where users look at when interacting with all different kind of products. After a careful calibration, eye trackers can measure the movement of the pupil and ultimately detect where on a screen or product the eye focuses.

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A prototype can be of low or high fidelity. The fidelity of a prototype describes the degree to which it is finalized or similar to the final product. The more features of the final product a prototype has, the higher its fidelity. A paper sketch of a website is of low fidelity while a clickable simulation of a website which already shows design and functionality is of high fidelity.
Fitts’s Law
An empirical (based on observation, rather than pure logic) model of human movement, used to predict the time required for a user to point at an object on the screen of the computer with a pointing device, ie. mouse. Popular within the design of GUIs, the importance of this model has risen in recent years with the prevalence of this interface form. The model takes into account factors such as distance from the object and the object’s size to calculate how easily and efficiently a user can select it. This can be important when designing call for actions, increasing conversion rates on web pages for example. First being formulated in 1954, it remains relevant today despite the rise of touchscreen devices.
Five Second test
The rule of thumb is that people make their mind up about a website within the first 5 seconds of first visiting. This gives the designer 5 quick seconds to show the user why they should stay, why this is the site for them. In comes the 5 second test. This usability test is as simple as it sounds; Let a participant view a screenshot for 5 seconds, then ask them to recall which features they remember. This allows the designer to create easily identifiable call to actions and visuals. Capturing the visitor’s attention as quickly as possible.
Flat Design
Flat Design has its roots in 1950s Switzerland. The ‘Swiss style’ design philosophy emphasizing minimizing, cleanliness and content organisation. Its fundamentals consisting of a grid system for aligning content and San-Serif fonts (ie. Helvetica – Latin for ‘Switzerland’).
What we see now with Flat Design are these principles being applied in the Digital world. The removal of the ‘bells and whistles’, leaving us only what is important: Color, Shape and Content. A presentation method which is effective at being both minimalist and beautiful.
The fold of a website is an imaginary line that divides your website into two parts. The part above the fold is what you see immediately after loading a website in your browser. The part below the fold can only be seen after scrolling the page. So depending on the size of your browser window, or more dominantly your screen, the position of the fold can vary. Make sure to place your most relevant information and links above the fold.
The footer of a web page can be seen as counterpart to the header. Together, the two form a frame around the content of the web page. The footer is located at the very bottom of the web page and usually contains information of minor importance. This information includes for example legal statements, terms of use, copyright information, etc. Just like the header, the footer of a web page usually is the same for the whole website.
Quite possibly the most prevalent error on the internet. So prevalent in fact, that in recent years joke 404 pages are not uncommon as a light method of relieving the stress of a situation. The “404 not found” error is a server response to being unable to return a requested link to a user – because of a dead or broken link, due to a page being moved or deleted. Hence becoming one of the most recognisable errors we find when browsing. The non-threatening nature of the 404, and its abundance has led to the rise of comical 404 pages. A great, and very strange, example of such a page can be found here and is definitely worth a look!

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Gestalt’s Laws of Grouping
Gestalt’s laws of grouping are a set of principles or laws that describe how humans perceive patterns in objects. Gestalt meaning “whole’ in German refers to the theories of visual perception generated by German psychologists who believed a whole image is greater than some of it’s parts. The 4 laws consist of grouping images depending on their similarity, proximity, continuity and closure.
GUI is an abbreviation for Graphical User Interface – a type of user interface that typically makes use of Windows Icons Menus and a Pointer (WIMP) to act as an interface between the user and an electronic device. In fact GUI interfaces take advantage of these devices’ capability to render graphics so as to provide a more intuitive environment for users. However, GUI interfaces may not necessarily be more usable than Command Line Interfaces (CLI) – environments in which users interact with electronic devices by typing in commands. This is because users who know the Command Language being used by a device can typically interact with that device more effectively and efficiently.

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The header of a web page describes a structural element which helps better divide the content. The header is always located at the very top of the web page and usually includes a company’s logo, the main navigation, and some visual elements. The header ideally gives a quick overview of the purpose of the website and it’s content. Besides, a header can be used to get users engaged and interested. Usually, the header is a reoccurring element on all web pages of a website.
A heatmap is a visual representation of any sort of accumulations. In user research, these heatmaps can for example identify certain areas of interest on a digital interface, such as a website. As with a thermal camera, color schemes form around a ‘hot spot’, which can be a certain element that draws people’s attention. The more attention an elements gets, the more intense the color gets. Heatmaps are a great visual way to analyze and interpret the results of a user test. For example, the eye-tracking technique uses heatmaps to identify where people look on a test interface.
Heuristic Evaluation
Created by Danish usability consultant Jakob Nielsen, this involves checkmarking an interface against a predefined set of ‘Heuristics’; criteria which the interface must meet. The interface is judged by one or more reviewers, and is provided with a score for each heuristic – based on their estimated impact on user performance or acceptance; the results identifying any problems within the interface.

The simplicity and low cost of this evaluation method offer its main advantage, being extremely effective in budget and time restrictive situations, the only major downside being that they may require personnel with a certain level of knowledge and experience in order to be effective.

The homepage describes the start page of a website. This means that visitors of the website are supposed to visit the homepage first before browsing to other web pages. All web pages of the website should be easily accessible through the homepage. The URL (Uniform Resource Locator) of a Website usually leads to the homepage.
Hover State
A Hover state is simply the change of state in an object within a UI when the cursor is hovered over it. A frequent seen example being the ‘flow’ of the Dock on the Mac interface. The majority of the time, especially online, we use this technique to show the user which parts of the screen are selectable. The change of state alerting our user that this thing can indeed be clicked.
Hyper Text Markup Language (HTML) is the main markup language used for creating web pages and other web-based content. Without it, this page would be little more than basic clump of text.
Originally built by Tim Berners-Lee, the internet pioneer, its foundations were first implemented in 1990. This first iteration has evolved constantly overtime, as we currently sit on version 5.0/4.
HTML is written in the form of ‘tags’ around text. These tags shape, format and compose the page’s content. This could be text, image, audio or visual content. Default characteristics of the HTML-shaped page are determined by the web browser, these characteristics enhanced by use of CSS(Cascading Style Sheets). Rarely these days would we see a page built of purely HTML, with CSS providing the gloss. Yet even non-programmers may frequently encounter it. Many text inputs (ie. forums) still require a basic understanding, and even this text is formatted in HTML in order to differentiate titles, images, links, and whatever else.
Human Computer Interaction (HCI)
Obviously, HCI has something to do with people, computers, and interaction. Basically, it is all about how people use computers. HCI looks at human usage of interactive computing systems from a 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.

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Incentives are usually given in return for the participation in a user test. Incentives can be an agreed amount of money as well as any kind of present. Incentives are a big motivational factor for participants. If you give something away, people are way more willing to give something back in return. In case you want to collect quantitative data and need a lot of participants, you can for example raffle a prize for every 20 participants.
Infinite Scrolling
With the vast amount of data contained in modern websites, designers need a technique to manage page load times. Left unchecked, loading thousands of items at one time would be disastrous to the user experience – not to mention the monotony of endlessly hitting ‘next page’.

In comes Infinite scrolling. The basic functionality is that, as the user scrolls through the content, more content is loaded automatically. This creates a seamless – ‘infinite’ – list of data. Infinite scrolling ensures the user can be shown as much data as possible. Whilst also ensuring this data is provided in bitesize chunks, easy for whatever device being used to handle.

Information architecture
Information architecture describes the presentation of information on a website. This includes three main aspects:

1. The structure of the information, such as which elements to link and which categories to group them in.
2. The design of the navigation to ensure that users understand it.
3. The wording of different content elements and categories that correspond with users’ expectations.

A good information architecture ensures that website visitors quickly find what they are looking for.

Informed consent
Informed consent describes the ethical aspect of user testing, which ensures that participants participate out of free will after they have considered all aspects of the research. Be it for educational, nonprofit, or commercial reasons, whenever you collect data, make sure you inform your participants about the nature of the research, their role as participants, and how you intend to use the test results. Never go public with e.g. video or audio material of a test session without having your participants consent.
Interaction Design
When we hear the term Interaction design, we might be tempted to believe that it is the actual design that 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 comprises the conception and functionality of the interface which facilitates the communication between the user and the interactive system.
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 should be repeated until users find no more issues that need to be improved.

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No Terms Starting With “J”
Currently, there are no terms associated with this character. Do you know one?

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Kano model
The Kano model is a theory/tool created by Japanese Professor Noriaki Kano, used to prioritise customer needs when developing products. The model consists of categorising features into five sections: Must have, one dimensional, attractive, indifferent and reverse. This enables designers to create products that are innovative but most importantly meet customer needs.
KLM, which stands for Keystroke Level Model is a simplified version of the GOMS (Goals, Operators, Methods and Selection Rules) technique. Devised by Card and Moran in 1983, KLM provides a time estimation for keystrokes associated with data input tasks. Using KLM, a task is first broken down into a combination made up of a sequence of 6 classes – K (keypress), P (pointing a mouse to an object), B (pressing or releasing the mouse button), M (mental preparation), H (moving hands to home position on the keyboard) and R (waiting for a system response). Each of these classes has an approximate time associated with it. For example P=1.10s, B=0.10s, H=0.40s whilst M=1.20s. Thus, to estimate the time required to do a task, one would simply need to add the time associated with each of the classes required to complete that task. For example, a task that is made up of P,P,B would require 2.3s to complete (1.10 + 1.10 + 0.10s)

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Likert scale
A Likert scale is a special kind of survey question. Instead of asking something, people are given a set of related statements. These statements can be rated according to the extend to which one agrees or disagrees with each of them. Likert scales usually includes a range of answers going from 1 = I strongly disagree to 5 = I strongly agree.

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Main body
The main body of a web page describes the area in the middle of the page (between the header, the footer and optional side bars) that contains the actual content.
Metaphors are comparisons of two concepts that are not similar for most parts, but that have certain mental schemata in common. Metaphors consist of two parts: a vehicle and a tenor. The vehicle is a concept that we are familiar with. The tenor is the concept to which the metaphor is applied. Because of visual, functional, or structural similarities, we can transfer our knowledge about the vehicle to the tenor and consequently make sense of this unfamiliar concept. Metaphors can for example be found in language, images, or gesture.
Mind map
A mind map usually visualizes the results of a brainstorming. You start with one central term and going from there, you add all different ideas. Link ideas that seem to be connected by grouping them or drawing a line between them. A mind map reflects connected ideas around a certain topic, as they are memorized in your mind.
A mockup is the followup step after a wireframe. It includes the actual design and therefore represents the final user interface. Mockups can either be static images, or simulate functionality to different degrees. Mockups can be used to test the user interface at low development costs.

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In UX, navigation how a user travels through a website or software in order to reach their goals. The easier it is for the user to navigate, the faster they will find what they are looking for. Poor navigation systems will undoubtedly lead to the frustration of your visitors and damaged conversion rates. Visitors want to find what they are looking for as quickly as possible, and if one site can’t lead them to it, there are a plethora of others offering the same service.

When optimizing their navigation, websites often use subtle tricks to lead the user to where they need them to be. An eCommerce site, for example, may aim to make navigation towards its profit generating areas much more visible than others.

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Observational Study
An observational study involves watching people’s behaviour to discover patterns in their actions. Insights can help shape the future design process, building based on a user’s behaviour.
Observation marries well with User Centred Design (UCD), where the user is at the centre of the design process. For example: by studying people working in an office environment, we can better understand their interactions and usage of computers. Leading to systems being built more adapted to their needs.
A relatively inexpensive study method, observation allows designers to gain a basic understanding of the situation quickly. Perfect for discovering what is happening, it ignores the why. A key limitation of the method.
Occam’s Razor
Occam’s razor is a problem solving principle which argues that simplicity is better than complexity and encourages 
Open question
In an interview or a survey, you can ask different kind of questions. One of them are open questions. Open questions can be answered with an open answer. This means people use their own words to come up with an answer. With open questions you get a lot of different answers throughout a survey and even though it might take a little effort to analyze them all, they will give you valuable, qualitative insights. Assuming you asked the right questions.

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Pagination is a web design methodology whereby content, such as an article, is split up and linked together by pages. This is essentially the opposite to infinite scrolling. Historically this method was prevalent on the internet. Paging formed an effective method for bypassing slow internet speeds and the consequently slow page load times. By loading the content one page at a time, it is split up and thus the stress on the system decreases. However, as web technologies have advanced: higher performances machines, faster internet speeds, and the advent of infinite scrolling have largely surrendered this technique as an internet artefact.
Paper Prototyping
A throwaway prototyping method; wherein the designer can quickly sketch, test, then resketch ideas on paper. The low cost and speed of this technique allows rapid evolutions to be made within the prototype, reducing the costs and annoyance associated with problems occurring later in the design process. Users/testers often feel more open to express their feelings about a system at this stage due to the interface not having a polished look.
Parental consent
Parental consent describes the consent required from parental authorities in case of underage test participants. As the legal age differs between countries, make sure to check for your own country, whether you need parental consent or not. In some cases, e.g. when doing research with positive effects, consent given by under age participants can be sufficient.
The Pareto Principle or 80/20 Rule
This harks back to Italian economist Vilfredo Pareto, who in 1906 observed that 80% of the land in Italy was owned by 20% of the population; developing the principle through observing that 20% of the pea pods in his garden contained 80% of the peas.

Though this sounds like crazy reasoning, it is used as a common rule of thumb in business and can also be applied to Usability: Users will use 20% of your products features, 80% of the time; and thus as a designer, the majority of your design efforts (80%) should be spent on the most important 20% of the product.

This principle, interestingly, has some mathematical foundation; roughly followed by a power law distribution – known as Pareto distribution.

Passive informed consent
Especially for quantitative studies, that don’t involve any ethical concerns, passive informed consent can be very convenient. Passive consent implies someones participation in a study. However, when going with passive consent for a research, it is still important to offer sufficient information and a simple way for people to resign. Implied participation does not mean it’s obligatory.
Personas are concrete descriptions of possible users. A persona usually includes basic demographics, a picture, and any information that help bring the fictive person to life. This can be characteristics to describe the personality, but also goals, preferences, and limitations that can be directly linked to the product or system under development. Through a variety of different personas, a target group becomes more concrete. Especially in the beginning of a design process, personas help to pin down specific user requirements.
Pilot test
A pilot test is a pretest that is performed to conform the quality of a usability test. Just like you test your user interface, make sure you focus your user tests on your participants. By pretesting, you can identify if you focus on the right target group, if your questions are easy to understand, if the length of your test is appropriate, etc.
Priming describes the exposure to a stimulus, which activates mental pathways in our brain. It’s like we open a drawer full of information linked to a certain stimulus. These stimuli can be anything, such as words, pictures, colors, or people. Now if we are exposed to a similar stimulus at a later point of time, this drawer might still open, which means we can easily access the information inside. This leads to a priming effect.
A prototype is a provisional version of a product or system that is used to visualizes ideas and test functionalities. Prototypes are used in all different fields and in different stages of the development of a product. The idea behind prototyping is to validate ideas and concepts early in the development process in order to save time and money. Changes in prototypes can be made quite easily compared with changes in fully functional products.

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Qualitative research
Qualitative research is used to learn about, interpret and understand a subject of interest. Qualitative data offers insights into how individual users think and feel, what they like or dislike, and how they for example go about a certain task. The most important thing about qualitative research is that it can get you answers about the why: Why do users behave the way they do? Why don’t they understand something? Why don’t they like something? etc.
Quantitative research
Quantitative research aims at investigating quantitative relationships of social phenomena. Quantitative data includes any numerical data like statistics or percentages. In user testing, quantitative data is used to make assumptions about the whole. By taking measures from a representative user group, assumptions can be made about all users.

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Rapid Prototyping
Rapid prototyping is the rapid development of creating interactive prototypes for testing. It is usually a cyclic process that repeats stages of designing, analysis and development.
The reliability of a research indicates how reliable the results are. Reliable results are consistent over time and different researchers. A research should be set up in a way that anyone can duplicate it at anytime and get the same results.
Responsive Design
Responsive Design is a web design approach whereby the site’s design adjusts to the user’s behaviour and needs, based on: Platform, Screen size, Resolution, and Orientation. The site should *respond* to the user’s needs. If they move from their desktop to the iPad, their experience should not suffer. It works both ways: Your visitors have a greater user experience, and it saves you from developing multiple sites for each device. This is achieved using an intelligent mix of CSS media queries and flexible grids, layouts and images.

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Satisficing mostly appears in usability research with children. Children don’t want to disappoint adults, or authority figures. Rather than answering truthfully, they tend to give answers that they think they are expected to give. This is especially true for negative aspects, which makes it even more difficult because usability issues are mostly negative. Make sure your participants know, that they cannot do anything wrong or give wrong answers. Not they, but the test interface is being tested.
Selection bias
Selection bias occurs in usability studies when your selected test participants either don’t represent your target group, or when they are not selected randomly. Examples of non random samples can be an imbalance in aspects like gender, expertise, or geographical location, or only people, who are already extremely enthusiastic about product, agree to participate in your study. A selection bias can influenced and possibly falsify your test results.
SEO stands for Search Engine Optimization or Search Engine Optimizer. 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. Users, who look for anything you offer, need to find your website at the very top of their search results list. Through SEO you can increase your traffic by increasing the chance that people find your website.
A scenario describes how a persona interacts with a product or system to reach certain goals. Scenarios show how different personas use a product or system differently. Especially in early stages of the design process, scenarios help to identify user requirements and understand how users approach a task. Scenarios consider users’ personalities, their interests, abilities, and limitations, but also environmental aspects, that influence the interaction with a product or system.
The sitemap of a website gives an overview of all web pages that are included in the website. The sitemap shows how the different web pages are linked and helps the user gain a conceptual understanding of the site. Ideally, the sitemap is interactive and allows users to directly go to the different pages.
A UX design practice where real world objects are represented digitally, creating visual metaphors. A basic example are radio buttons; taken from their namesake. These mimic the buttons on old analog radios, where when selecting one preset channel, the other buttons would pop out. Skeuomorphs are particularly important in User Interface design, as they provide the user with objects they are familiar with in the real world – increasing familiarity within a system. Further examples include sliders (metaphor for analog sliders), software-based calendars (designed to appear as paper-based calendars) and tablet gestures (turning the pages of a book). Apple, under Steve Jobs, was a particular proponent of this digital design technique.
Storytelling is a very old and effective way of communicating. Stories can be told in many different ways, for example with words, in songs, or through pictures. They can be short, or long, and usually stories are in some way informing or entertaining and therefore easy to remember. Stories usually contain a plot, one or several characters, and a narrative point of view. Storytelling is used for different purposes, for example to entertain, to educate, to advertise, or as tool to manage change in an organization.

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Target group
A target group describes a certain group of people for whom a system or product is intended. The target group consists of future users who define the requirements for a product or system. A target group can be very specific and defined, or very broad. The more specific the target group, the more specific the product requirements that can be identified.
A task describes the means-ends process users engage in when using a system. Users have a goal which they try to reach by performing a certain task. A task can stand alone or be combined in a series with other tasks. Task oriented user testing includes tasks that are expected to be identical with real world tasks. Users are asked to perform a task, which allows insights into how well a system is designed to meet the requirements users have so they can reach their goals.
The task-flow describes how different tasks are connected with each other. Instead of performing only one task, users perform a series of tasks in order to reach one goal. A good task flow indicates that the user does not get interrupted and reaches his or her goal as directly as possible.
Think-aloud protocol
Think-aloud protocol is a research technique that is mainly used for user testing. Test participants are asked to verbalize their thoughts, actions and feelings while interacting with a test interface. This way, test moderators can get detailed information about what participants expect, why they perform certain actions, or what bothers them.
Think-aloud protocol
Think-aloud protocol is a research technique that is mainly used for user testing. Test participants are asked to verbalize their thoughts, actions and feelings while interacting with a test interface. This way, test moderators can get detailed information about what participants expect, why they perform certain actions, or what bothers them.
Thoughtless Acts
A thoughtless act describes a person’s subconscious, instinctive reaction to their environment – an act without thought. Specifically reactions where a person interacts in a way we wouldn’t expect – creating solutions for themselves. These acts show how a person interacts with, and experiences their surroundings.

Common examples of this phenomena in the real world include using a newspaper or book to shield the sun whilst sunbathing, or using a cold can of soda on one’s forehead to cool down. These are not the intended uses for the objects, but perform the task required of them.

These unexpected interactions with the real world offer us great insight into how people subconsciously experience their surroundings. Offering a valuable tool when designing with usability in mind.

Some great examples of Thoughtless Acts [can be found here](

Training Wheels User Interface
Training wheels (or stabilisers as we call them in the UK), are those small wheels added to a child’s bike to aid them when learning to ride. Ensuring the child is gently eased into the process, and limiting damage. If only this same system could be applied to software…
Training Wheel User Interfaces are the answer. Their aim: to only reveal the most basic and essential of functions to the user. Hiding the more advanced features until the user has a better understanding of what they are doing. This allows users to play around and experiment more effectively, ultimately aiding their learning of this new system.

Later, when they feel more confident and know what they are doing the more advanced functionality can be enabled. A study by the grandaddy of UX, Jakob Nielsen, declared that through using a Training Wheels UI, learning can be increased by upwards of 69% when compared to throwing advanced features at someone.

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Unique site visitor
The number of unique site visitors indicates how many people have actually visited a web page. Web analytic tools identify visitors by their IP address, which makes it possible to not only measure traffic, but also see if visitors visit a site only once or several times. If visitors return, they are still counted as one unique site visitor.
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. Now this is a very official sounding definition. In other words, good usability implies that users can easily use a product and by doing so, reach their goals quickly and without falling into despair. Some aspects of usability overlap with the user experience of a system. Good usability should also include a good user experience.
Usability Engineering
Usability engineering basically comprises the execution of all aspects related to 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. Besides, usability engineering links the challenges claimed by the user with often inflexible organizational processes.
Usability lab
A usability lab is a laboratory set up for usability testing. Usually, a usability lab consists of a test and an observation room. The two rooms are either divided through a one-way mirror, or cameras are installed, so people in the observation room can follow the test. The test room is at least equipped with a microphone and a camera that record how the test person interacts with a system. Usability labs can also be equipped with more advanced material such as an eye-tracker.
Use case
A use case describes a very specific interaction between user and system. It usually includes one or more tasks that a user engages in to reach a certain goal. With use cases, common tasks are identified and functionality, usability, and the UX of a system can be tested.
User Centred Design (UCD)
UCD describes the development process of any kind of product or user interface that has its focus on the end user. 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.
User Acceptance Testing (UAT)
Colloquially referred to as Beta testing in the Software industry, User Acceptance Testing is aimed at verifying whether a solution works for the user ie. Test the user accepts the proposed solution.

It is aimed at verifying a system meets the goals and expectations required of it. As one the final stages in the development cycle, users test it as if being used in real world conditions. This final stage of verification ensures that everything works as required when it enters the big wide world.

Again, due to it being the final stage of development, and due to the very nature of the test, testers are often end users or clients of the potential system. Gaining their acceptance is key in ensuring the system is desirable and key in building confidence prior to launch.

User Experience (UX)
The UX is the subjective feeling users get when using a product, system, or service. User experiences come from users’ individual perception of different aspects such as appeal, information content, accessibility, credibility, relevance, ease of use, etc. Through a good user experience, you can motivate your users, engage them in actions, make sure they return to your site, and more.
User Flow
User Flow studies both where you plan your users to begin and end on their journey through the website. It is a diagram of states. Not only is it about what you wish your user’s journey to be, but about their expectations. With input from your users, you can design their journey to meet their needs, as intuitively as possible. User Flow helps you to better understand where your users are going, what their end goal is, and how this will be achieved.
User Interface
The user interface 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 a high user experience, a user interface needs to be usable, intuitive and to a certain degree fun to use.
A user is a person who interacts with a product or system. The user can also be called end user because he or she eventually purchases, consumes, and uses a product or system.

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The validity of a research indicates how valid the results are. Valid results are not a matter of interpretation but they are clear and explicit. The validity of a usability test is the extent to which it actually measures what it was intended to measure.
Visual Weight
Visual weigh is the visual impact of an image in a composition. Primary information is usually heavier than other elements in a composition so that it draws more attention from users. The visual weight of an object can be adjusted in value by changing the colour, contrast, size etc.

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Web Analytics
As technologies have become more complex, it has become necessary – and possible – to better measure user’s behavior on a site. Studying User Flows, geographic locations and the success of call to actions. Analytics Help designers to understand their user’s needs, and how design decisions shape their experience with the site. Though it is nearly impossible to exactly understand behavior, analytics allow for us to collect and refine a tremendous amount of data which can be analysed for clues.
Web page
A web page can be seen as online document, which makes up one page within a website. A web page is written in HTML (Hyper Text Markup Language) or XHTML (eXtensible Hyper Text Markup Language). Markup language is interpreted by browsers and displayed as visual and audible web pages. The actual layout of the web page is defined through CSS (Cascading Style Sheets), scripts, and images. Web pages are linked together through so called hyper links.
A weblog can either be a website itself, or part of one. Weblogs can function as online diaries, or as platforms for marketing reasons and discussions. A blog entry is called ‘blog post’. Usually, new blog posts appear at the very top, pushing older posts further to the bottom of the page. Like other web pages, blogs make use of different content such as text, hyperlinks, pictures, and more. What makes blogs special is their interactive nature. Visitors can react on blog posts by leaving comments.
A website is a collection of linked web pages that offer content in differing digital forms such as text, images, audio or videos files. Every website is assigned to a specific address, the so called Uniform Resource Locator (URL). Through this URL, a website can be accessed via the Internet or other, e.g. local networks. A website is hosted at one or more web servers.
Widgets are on-screen devices used to interact with the web page or convey information to the user. Early internet examples include the historic page view counter image and many banner advertisements. As the web has evolved however, these have become more intuitive and lend more to the user experience. Aside from the web, they can also be found on operating systems. Most notably, widgets formed a key component of the Windows Vista OS – only for used to be warned later by Microsoft that they posed a security risk.

Current examples you may come across on the web include: radio buttons, sliders, push buttons, or our very own Usabilla Live!

A wireframe shows a user interface in an early and conceptual stage. Wireframes can be simple sketches, or digital drafts. They structure the interface and indicate the positioning and size of navigation and content elements. This early step of the design process is very helpful to test the structure of a user interface at a low level of design and development costs.
Wizard of Oz Experiment
Conceived in the 1980’s by John F. Kelly, the Wizard of Oz experiment utilized one-way mirrors to enable the tester separation from the participant. The original use was in the development of natural language processing algorithms. The Examiner originally took the place of the machine as the participant fed in natural language. The experiment bypassed the need for an extensive algorithm to already exist, and allowed the examination process to be much shorter – due to the sub-par processing ability of machines at the time.

Over time, the algorithm was built up to respond for intuitively with the natural language until a point was reached whereby the man behind the curtain needn’t be there. Today, the experiment still sees effective use in the testing of Speech and Handwriting recognition.

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No Terms Starting With “X”
Currently, there are no terms associated with this character. Do you know one?

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You are here indicator
This is a method of relaying a user’s current position within an ‘interface’, back to the user. Interface being a loose term… This could be anything from the large ‘You are here’ arrow on a map, to the highlighting of an element within a menu.
In computing, this was historically essential for use in menus. Before the mouse, navigation using arrows meant this was the only way of knowing your place. The mouse now allows us a secondary indicator, but the original remains key. By having clickable elements highlighted by hover-states, we know what we’re clicking. Helping users to orientate themselves in large information spaces.

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ZUI is an acronym for Zooming User Interface – a type of Graphical User Interface (GUI) in which users can zoom in and zoom out so as to see hyperlinked or multivariate information in more or less detail. This facilitates navigation through vast amount of data. Although users once found it difficult to navigate along the z-axis when using a computer screen, widespread use of 3D applications such as Google Maps have paved the way for ZUI.

Creative Commons License
The Usability ABC by Usabilla & Justin Mifsud is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.


  1. Robert Visser

    Any thoughts on defining when it’s better or more appropriate to use user interface (UI), UI design or interaction design? I’ve seen them used interchangeably. Regardless, of whether they are or are not synonyms wouldn’t it be helpful for the list of definitions?

  2. Sabina

    Hi Robert,

    Good question. I think user interface design and interaction design do to some extend cover a similar issue: how users interact with an interface. However, I would define UI design as more focused on the interface while interaction design puts more focus on the user. Meaning that UI design includes not only the interface itself, but also other aspects like its positioning, characteristics of the material, or external influences such as light reflection, temperature, etc. Interaction design on the other hand takes the user and his abilities, limitations and foreknowledge into account.

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  4. Sabina Idler


    How very nice of you to say, thank you! We’ll do our best to keep it up!

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    Usabilla test cases & other articles reveal lots of interesting information which is very hard to find by surfing internet. Thanks for your great efforts Sabina!

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