Usability Terms | Satpal Sharma

Usability Terms

A consolidation of popular usability terms. I think apart from this huge list there still be some terms which I haven’t defined here. Feel free to mail me those and I’ll be happy to put them here.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Assistant/ Wizard

A special type of dialog box that takes a user through a step-by-step procedure. Intended to simplify what might otherwise be a more complex procedure if performed, for instance, through direct manipulation.

“Assistant” is the term used in the Mac OS. “Wizard” is the term used in Windows.

Adaptive Interfaces

User Interfaces that change over time, in response to how they are used, to improve the quality of the interaction. Examples with current technology include speech and handwriting recognition systems that improve the accuracy of their recognition as they become familiar with the user’s style.

Adaptive systems also include those that detect common user tasks and make these tasks more accessible — making lists of recently-opened files is a very simple example of this. Any adaptive interface has, at some level of detail, a model of the user’s behavior that is refined, and provides an interaction that fits the behavior as best as it can.

Affordance

A situation where an object’s sensory characteristics intuitively imply its functionality and use.

A button, by being slightly raised above an otherwise flat surface, suggests the idea of pushing it. A lever, by being an appropriate size for grasping, suggests pulling it. A blinking red light and buzzer suggests a problem and demands attention. A chair, by its size, its curvature, its balance, and its position, suggests sitting on it.

An affordance is a desirable property of a user interface – software which naturally leads people to take the correct steps to accomplish their goals.

The common psychological term for this is stimulus-response compatibility.

Card Sorting

Card sorting is a way to involve users in grouping information for a Web site. Participants in a card sorting session are asked to organize the content from your Web site in a way that makes sense to them. Participants review items from your Web site and then group these items into categories. Participants may even help you label these groups.

Ergonomics

A design tradition preceding human-computer interaction and strongly related. Ergonomics is often used relatively synonymously with “human factors”. It studies how to design human-machine systems with a concern for human needs, especially focused on work environments, efficiency, and safety. The field has a strong engineering flavor, with an emphasis on measurement of human performance parameters and physical properties, such as the measurement of human dimensions to determine the size and arrangement of desks and chairs, or the application of psychophysical parameters to set noise levels.

Ethnography

An approach to research which involves in-depth study through observation, interviews, and artifact analysis in an attempt to gain a thorough understanding from many perspectives.

Field Studies

The most valuable asset of a successful design team is the information they have about their users. When teams have the right information, the job of designing a powerful, intuitive, easy-to-use interface becomes tremendously easier. When they don’

t, every little design decision becomes a struggle. Field studies get the team immersed in the environment of their users and allow them to observe critical details for which there is no other way of discovering.

Fitts’ Law

T = k log2(D/S + 0.5), k ~ 100 msec.

T = time to move the hand to a target

D = distance between hand and target

S = size of target

Fitts’ Law is a model to account for the time it takes to point at something, based on the size and distance of the target object. Fitts’ Law and variations of it are used to model the time it takes to use a mouse and other input devices to click on objects on a screen.

Broadly, Fitts’ Law can be applied by designers to suggest moving target buttons closer and making them larger for extremely commonly used buttons. In detail, applying the formula can be extremely useful for exact design of time-critical applications.

Focus Group

A group of potential users or stakeholders in a product who are brought together to gather information as input to the design process. When the users are current users of a prior version of a product, the questions for them will usually focus on the use of that product. Typically the goal is to understand the users’ work processes and goals and gather functional and usability requirements for a product.

In contrast to interviewing individual users, a focus group offers the opportunity for the users, rather than the interviewer, to strongly determine what the important issues are for discussion. Focus groups offer the possibility that an unexpected comment from one person will lead to deeper insights from others. Focus groups are often more time-efficient than interviews, and when they involve stakeholder, they can be valuable for obtaining consensus on issues.

Focus groups are more difficult to guide than individual interviews and may suffer from groupthink problems, where the entire group gets focused on a topic of relatively little importance.

Gap Analysis

The analysis of the difference between a technology’s capabilities and the user’s needs. This is usually informed by a user needs analysis (usually the result of user observation and requirements analysis) and is used to produce usability objectives and a development plan.

GOMS

A family of techniques for modeling and representing the knowledge necessary for a person to perform a task. GOMS is an acronym that stands for Goals, Operators, Methods, and Selection Rules, the components of which are used as the building blocks for a GOMS model.

GUI

Graphical User Interface, pronounced “GOOEY”. A user interface that presents information graphically, typically with draggable windows, buttons, and icons, as opposed to a textual user interface, where information is presented on a text-based screen and commands are all typed.

It’s often assumed that GUI applications are inherently more usable than text interfaces, but that may not be true when GUI applications are not well-designed. Graphics enable more flexibility in design and enable certain useful interaction styles (like direct manipulation), but text-based applications may still be extremely usable if they are designed through a user-centered process: gathering information from users, carefully designing the interaction tasks, conducting user testing, etc.

Heuristic Evaluation

A technique for finding usability problems with a user interface. A small number of trained evaluators (typically 3 to 5) separately inspect a user interface by applying a set of “heuristics”, broad guidelines that are generally relevant. They then combine their results and rank the importance of each problem to prioritize fixing each problem. In Jakob Nielsen’s work, he identified 10 heuristics which are broadly helpful in spotting the vast majority of problems (though others may at times be useful). The 10 that Nielsen identifies are:

visibility of system status

match between the system and the real world

user control and freedom

consistency and standards

error prevention

recognition rather than recall

flexibility and efficiency of use

aesthetic and minimalist design

help users recognize, diagnose, and recover from errors

help and documentation

Hick’s Law

(1) H = log2(n + 1).

(2) H = Σ

pi log2(1/pi + 1).

H = the information-theoretic entropy of a decision.

n = the number of equally probable alternatives.

pi = the probability of alternative i for n alternatives of unequal probability.

The time it takes to make a decision is roughly proportional to H, the entropy of the decision (the log of the number of alternatives), i.e. T = k H, where k ~ 150 msec.

This can be used to make a time estimate for how long people will take to make a decision in using a user interface, such as choosing a menu item, choosing a tool, or selecting an item on a navigation bar. Cognitive modeling approaches such as GOMS apply this to making predictions of human performance.

Hierarchical Task Analysis

HTA or hierarchical task decomposition, HTD; breaking down the steps of a task (process) performed by a user, viewed at different levels of detail. Each step can be decomposed into lower-level sub-steps, thus forming a hierarchy of sub-tasks. The highest level of detail might be something like: open the word processor -> type your document -> print it -> quit. However, opening a word processor is not a one-step process. It might break down into something like: locate the word processing application icon -> click on the icon -> select Open from the File menu. A common level to break it down to is the “keystroke level”, where ever mouse movement, mouse click, and key click is identified. (see KLM, the keystroke level model).

High-Fidelity Prototype

A prototype that is quite close to the final product, with lots of detail and functionality. From a user testing point of view, a high-fidelity prototype is close enough to a final product to be able to examine usability questions in detail and make strong conclusions about how behavior will relate to use of the final product.

Human-Computer Interaction

A diverse scientific and applied field where the focus is on how people use computers and how computers can be designed to help people use them more effectively.

The subject is studied from a wide variety of perspectives from many diverse areas, including (among others): computer science, psychology, ergonomics, information sciences, graphic design, sociology.

Example HCI topics include: design tools, design methods, human information processing, collaborative work, information architecture, interaction techniques, and interaction devices.

Human Factors

The field that studies the role of humans in human-machine systems and how systems can be designed to work well with people, particularly with regard to safety and efficiency. Traditionally this field was from an engineering and industrial design perspective and was applied to industrial systems, such as airplane controls, factory systems, and car design.

Information Architecture

The organization of information; the field which studies how to organize information most effectively to help people find and use the information. For instance, how should websites be organized? What is the best way to design website navigation? How should pages be labeled and identified?

Interaction Design

The design of how a user communicates, or interacts, with a computer. Interaction designers focus on the flow of interaction, the dialog between person and computer, how input relates to output, stimulus-response compatibility, and feedback mechanisms.

This is in contrast to a visual designer, who may be trained in designing visualizations for static media but not necessarily in the dialog which is present in all interactive media. A “visual interaction designer” is a visual designer with interaction design skills. Interaction design is also in contrast to information architecture – an information architect looks at the organization of information to make the structure of a complex system easy to conceptualize and navigate, but is not usually focused, for instance, on low-level interactions. For example, an information architect may design the structure of an entire website, but not have as much interest in the design of individual pages and how users interact with forms and other controls.

Intuitive

A term used loosely to refer to user interfaces that are easy to understand without training. An interface may sometimes be intuitive due to some inborn perceptual skill (e.g. loud noises make us pay attention) or at least some common physical characteristics of the world which anyone would be familiar with (e.g. raised surfaces facilitate, or “afford”, pushing, while lowered surfaces do not). However, much of the time, an interface is only “intuitive” to the extent that it is familiar, or similar to some previous experience of the user, and this perspective is often the most useful for understanding what makes a design most successful — imitate familiar activities, objects in the world, or software that people already have experience with.

Iterative User Interface Design

Redesigning user interfaces on the basis of user testing can substantially improve usability. In four case studies, the median improvement in overall usability was 165% from the first to the last iteration, and the median improvement per iteration was 38%. Iterating through at least three versions of the interface is recommended, since some usability measures often decrease in some versions if the usability engineering process has focused on improving other parameters.

Low-Fidelity Prototype

A prototype that is sketchy and incomplete, that has some characteristics of the target product but is otherwise simple, usually in order to quickly produce the prototype and test broad concepts.

Mental Modal

Humans establish mental models of how things work, or how they would behave in a particular situation. For example, having been a student at a university for a while, a student can establish a “mental model” of attending a university. That is, he goes to classes, talks to his classmates about how to accomplish certain assignments, he knows how to interact with his professors, etc. Suppose now a virtual university is being offered to students for online courses, and a website is to be constructed for the virtual university. This website should understand and respect the “mental models” of targeted students in order to avoid confusion for the students to find their way around the virtual university.

Paper and Pencil Prototype

A paper sketch of a user interface with enough detail to make design decisions and usability evaluations, whether through a usability inspection, a focus group, or a simple user test.

Persona

A description of a specific person who is a target user of a system being designed, providing demographic information, needs, preferences, biographical information, and a photo or illustration. Typically, multiple personas are developed in the early stages of design that represent the spectrum of the target audience. Personas are one piece of a “scenario”, the other piece being a description of how this person would typically interact with the system being designed.

The point of developing personas is to avoid the trap of designing for the “average” user that doesn’t actually exist, and instead to make sure that the system will work for somebody specific rather than no one in particular.

Questionnaire

A form that people fill out, used to obtain demographic information and views and interests of those questioned. Questionnaires are especially good for collecting subjective data (e.g. “how much do you like this software?”) and are often more convenient and more consistent than personal interviews.

Requirements Analysis

Requirements analysis is a tool that can be used to ensure that designers capture all the whole-of-life needs of the product or system from the perspectives of all the stakeholders – the acquirer, the operator, the user, the maintainer and those who refurbish or dispose of the it at the end of it life. At the end of the process, the designers are left with a document listing the system requirements for a product design. From this document they can base much of their subsequent work.

Retrospective Testing

Additional “testing” after-the-fact. After a user testing session has been conducted and videotaped, retrospective testing is reviewing the tape with the user to ask additional questions and get further clarification.

Storyboard

A series of illustrations that represent a process, such as the steps of interacting with a computer or frames from an animation or movie. Storyboards are useful for presentations, such as with focus groups, and for checking that the steps of a process make sense once the details are sketched.

Style Guide

A reference that establishes the look-and-feel of a user interface by clearly defining the standards and conventions of that user interface. Style guides usually include the principles that guide the design of the interface, graphic layout grids, exact size and spacing of elements in the interface, fonts, colors, interactive behavior, standard text messages (such as error messages), and labeling standards.

Excellent style guides are available for most major operating systems. Specific style guides are often created for individual applications or websites to establish consistency in organization and visual standards, and to assist the user interface designer in communicating the design both to developers and to other designers who may be working on the same project in the future.

Task Analysis

A set of methods for decomposing people’s tasks in order to understand the procedures better and to help provide computer support for those tasks. The basic approach is to define the task and the goal of the task and then to list the steps involved. The level of detail in decomposing the steps is determined by how the analysis is going to be used.

Task analyses are useful for making time predictions for how long a task will take and for spotting potential errors (steps in the process which are extremely difficult or confusing). Task analyses are also good for spotting areas in a user interface that may have been overlooked or oversimplified. A task analysis is a fundamental part of a cognitive model of user performance, such as GOMS.

Usability

The characteristic of being easy to use, usually applied to software, but relevant to almost any human artifact. What makes an artifact easy to use? Broadly, something is easy to use to the extent that it effectively performs the task for which it is being used. Ease of use can be measured by how quickly a task is performed, how many mistakes are made, how quickly the system is learned and how satisfied people are who perform the task. Usability may also include factors such as safety, usefulness, and cost-effectiveness.

Usability Engineering

A methodical “engineering” approach to user interface design and evaluation involving practical, systematic approaches to developing requirements, analyzing a usability problem, developing proposed solutions, and testing those solutions.

Usability Evaluation

User-centered evaluations are accomplished by identifying representative users, representative tasks, and developing a procedure for capturing the problems that users have in trying to apply a particular software product in accomplishing these tasks. During the design/testing/development cycle of software development, two types of user evaluations are carried out.

Usability Testing

Same as user testing, but emphasizes that it is the property of being usable, not the user, that is being tested.

Usability testing encompasses a range of methods that examine how users in the target audience actually interact with a system, in contrast to analytic techniques such as usability inspection. In a typical approach, a user performs a variety of tasks with the application while an observer records notes on how successful the user is in performing each task: how fast users go, what mistakes they make, where they’re confused, what solution paths they take, how many learning trials are involved, and so forth.

Use Cases

A task analysis technique often used in software engineering. For each module of a system, common tasks are written up with the prerequisites for each task, the steps to take for the user and the system, and the changes that will be true after the task is completed. Use cases are especially useful for making sure that common tasks are supported by the system, that they are relatively straightforward, and that the system architecture reflects the task structure.

User Interface

UI; the parts of a computer system that a person uses to communicate with the computer. This includes the way the computer conveys messages to the person (output devices), the way the person talks to the computer (input devices), and the steps the person must perform to do their task.

User Interface Design

The overall process of designing how a user will be able to interact with a software application.

User interface design is involved in many stages of product development, including: requirements analysis, information architecture, interaction design, screen design, user testing, documentation, and help system design. User interface designers may require skills in many areas, including: graphic design, information design, software engineering, cognitive modeling, technical writing, and a wide variety of data collection and testing techniques.

User Interview

User Interview is a method for discovering facts and opinions held by potential users of the system being designed. It is usually done by one interviewer speaking to one informant at a time. Reports of interviews have to be carefully analyzed and targeted to ensure they make their impact. Otherwise the effort is wasted.

User Testing

A family of methods for evaluating a user interface by collecting data from people actually using the system.

A simple user test would be to bring in a small number of potential users of the software (4-5 minimum, 8-10 to be thorough, more if the problem space or audience is diverse) and have each person sit down and use the software to perform a series of tasks while an observer takes notes about what difficulties each user encounters. Typically, users are asked to think out loud while they work with the software to help the observers understand how the users think about their problems and how the interface could be improved.

More involved user testing may test more users, get as representative a selection of users as possible, try out a variety of tasks, control the testing environment in various ways (or test a more naturalistic work environment), use more careful or thorough measurement instruments (videotaping, recording keystrokes, etc.), or combine the testing with other methods of data collection, such as interviews of users.

User Profile

Characterization of a system’s target population providing information about the users that is useful in making design decisions. The information in a user profile is usually obtained through a questionnaire given to the target users. A typical user profile might explore, for instance, how much experience users have with computing or a particular piece of software, what type of physical limitations they have, how frequently they perform common tasks, or what education or reading level they might have.

User Studies

Any of the wide variety of methods for understanding the usability of a system based on examining actual users or other people who are representative of the target user population. Such methods include user testing, focus groups, surveys, interviews, observational studies and ethnographic methods, and diary studies.

Wireframes

(Website Design) A skeletal version of a website or product that represents navigational concepts and page content. The term is used in 2 broad ways:

A static wireframe or page schematic is a single drawing of an individual page template that shows the information components, especially the navigation, that will appear on a page, in a rough form, so that navigation components can be documented and assessed. The drawing may suggest a basic visual layout, but doesn’t commit to any specific appearance.

A dynamic wireframe is a set of cross-linked pages acting as a functional prototype of the final website without the graphical components and often with only sketchy text content (e.g. “Product description goes here.”). It is often accompanied by a tree diagram or flowchart of the website. The wireframe does not address visual design or page layout.

(3d graphics) a 3-dimensional structure displayed by showing lines for each of its edges without representing surfaces or lighting.

Share or Bookmark this: