User interface (UI) design or user interface engineering is the design of user interfaces for machines and software, such as computers, home appliances, mobile devices, and other electronic devices, with the focus on maximizing usability and the user experience. In computer or software design, user interface (UI) design primarily focuses on information architecture. It is the process of building interfaces that clearly communicate to the user what's important. UI design refers to graphical user interfaces and other forms of interface design. The goal of user interface design is to make the user's interaction as simple and efficient as possible, in terms of accomplishing user goals (user-centered design). User-centered design is typically accomplished through the execution of modern design thinking which involves empathizing with the target audience, defining a problem statement, ideating potential solutions, prototyping wireframes, and testing prototypes in order to refine final interface mockups.
User interfaces are the points of interaction between users and designs.
Interface design is involved in a wide range of projects, from computer systems, to cars, to commercial planes; all of these projects involve much of the same basic human interactions yet also require some unique skills and knowledge. As a result, designers tend to specialize in certain types of projects and have skills centered on their expertise, whether it is software design, user research, web design, or industrial design.
Good user interface design facilitates finishing the task at hand without drawing unnecessary attention to itself. Graphic design and typography are utilized to support its usability, influencing how the user performs certain interactions and improving the aesthetic appeal of the design; design aesthetics may enhance or detract from the ability of users to use the functions of the interface. [1] The design process must balance technical functionality and visual elements (e.g., mental model) to create a system that is not only operational but also usable and adaptable to changing user needs.
Compared to UX design, UI design is more about the surface and overall look of a design. User interface design is a craft in which designers perform an important function in creating the user experience. UI design should keep users informed about what is happening, giving appropriate feedback in a timely manner. The visual look and feel of UI design sets the tone for the user experience. [2] On the other hand, the term UX design refers to the entire process of creating a user experience.
Don Norman and Jakob Nielsen said:
It's important to distinguish the total user experience from the user interface (UI), even though the UI is obviously an extremely important part of the design. As an example, consider a website with movie reviews. Even if the UI for finding a film is perfect, the UX will be poor for a user who wants information about a small independent release if the underlying database only contains movies from the major studios. [3]
User interface design requires a good understanding of user needs. It mainly focuses on the needs of the platform and its user expectations. There are several phases and processes in the user interface design, some of which are more demanded upon than others, depending on the project. [4] The modern design thinking framework was created in 2004 by David M. Kelley, the founder of Stanford’s d.school, formally known as the Hasso Plattner Institute of Design. [5] EDIPT is a common acronym used to describe Kelley’s design thinking framework—it stands for empathize, define, ideate, prototype, and test. [6] Notably, the EDIPT framework is non-linear, therefore a UI designer may jump from one stage to another when developing a user-centric solution. Iteration is a common practice in the design thinking process; successful solutions often require testing and tweaking to ensure that the product fulfills user needs. [7]
Common areas of interest include:
The Nielsen Norman Group, co-founded by Jakob Nielsen and Don Norman in 1998, promotes user experience and interface design education. Jakob Nielsen pioneered the interface usability movement and created the “10 Usability Heuristics for User Interface Design.” [9] Usability is aimed at defining an interface’s quality when considering ease of use; an interface with low usability will burden a user and hinder them from achieving their goals, resulting in the dismissal of the interface. To enhance usability, user experience researchers may conduct usability testing—a process that evaluates how users interact with an interface. Usability testing can provide insight into user pain points by illustrating how efficiently a user can complete a task without error, highlighting areas for design improvement. [10]
The dynamic characteristics of a system are described in terms of the dialogue requirements contained in seven principles of part 10 of the ergonomics standard, the ISO 9241. This standard establishes a framework of ergonomic "principles" for the dialogue techniques with high-level definitions and illustrative applications and examples of the principles. The principles of the dialogue represent the dynamic aspects of the interface and can be mostly regarded as the "feel" of the interface.
The concept of usability is defined of the ISO 9241 standard by effectiveness, efficiency, and satisfaction of the user.
Part 11 gives the following definition of usability:
Effectiveness, efficiency, and satisfaction can be seen as quality factors of usability. To evaluate these factors, they need to be decomposed into sub-factors, and finally, into usability measures.
The information presented is described in Part 12 of the ISO 9241 standard for the organization of information (arrangement, alignment, grouping, labels, location), for the display of graphical objects, and for the coding of information (abbreviation, colour, size, shape, visual cues) by seven attributes. The "attributes of presented information" represent the static aspects of the interface and can be generally regarded as the "look" of the interface. The attributes are detailed in the recommendations given in the standard. Each of the recommendations supports one or more of the seven attributes.
The user guidance in Part 13 of the ISO 9241 standard describes that the user guidance information should be readily distinguishable from other displayed information and should be specific for the current context of use.
User guidance can be given by the following five means:
User interface design has been a topic of considerable research, including on its aesthetics. [11] Standards have been developed as far back as the 1980s for defining the usability of software products. One of the structural bases has become the IFIP user interface reference model.
The model proposes four dimensions to structure the user interface:
This model has greatly influenced the development of the international standard ISO 9241 describing the interface design requirements for usability. The desire to understand application-specific UI issues early in software development, even as an application was being developed, led to research on GUI rapid prototyping tools that might offer convincing simulations of how an actual application might behave in production use. [12] Some of this research has shown that a wide variety of programming tasks for GUI-based software can, in fact, be specified through means other than writing program code. [13]
Research in recent years is strongly motivated by the increasing variety of devices that can, by virtue of Moore's law, host very complex interfaces. [14]
Usability testing is a technique used in user-centered interaction design to evaluate a product by testing it on users. This can be seen as an irreplaceable usability practice, since it gives direct input on how real users use the system. It is more concerned with the design intuitiveness of the product and tested with users who have no prior exposure to it. Such testing is paramount to the success of an end product as a fully functioning application that creates confusion amongst its users will not last for long. This is in contrast with usability inspection methods where experts use different methods to evaluate a user interface without involving users.
In the industrial design field of human–computer interaction, a user interface (UI) is the space where interactions between humans and machines occur. The goal of this interaction is to allow effective operation and control of the machine from the human end, while the machine simultaneously feeds back information that aids the operators' decision-making process. Examples of this broad concept of user interfaces include the interactive aspects of computer operating systems, hand tools, heavy machinery operator controls and process controls. The design considerations applicable when creating user interfaces are related to, or involve such disciplines as, ergonomics and psychology.
Usability engineering is a professional discipline that focuses on improving the usability of interactive systems. It draws on theories from computer science and psychology to define problems that occur during the use of such a system. Usability Engineering involves the testing of designs at various stages of the development process, with users or with usability experts. The history of usability engineering in this context dates back to the 1980s. In 1988, authors John Whiteside and John Bennett—of Digital Equipment Corporation and IBM, respectively—published material on the subject, isolating the early setting of goals, iterative evaluation, and prototyping as key activities. The usability expert Jakob Nielsen is a leader in the field of usability engineering. In his 1993 book Usability Engineering, Nielsen describes methods to use throughout a product development process—so designers can ensure they take into account the most important barriers to learnability, efficiency, memorability, error-free use, and subjective satisfaction before implementing the product. Nielsen’s work describes how to perform usability tests and how to use usability heuristics in the usability engineering lifecycle. Ensuring good usability via this process prevents problems in product adoption after release. Rather than focusing on finding solutions for usability problems—which is the focus of a UX or interaction designer—a usability engineer mainly concentrates on the research phase. In this sense, it is not strictly a design role, and many usability engineers have a background in computer science because of this. Despite this point, its connection to the design trade is absolutely crucial, not least as it delivers the framework by which designers can work so as to be sure that their products will connect properly with their target usership.
Donald Arthur Norman is an American researcher, professor, and author. Norman is the director of The Design Lab at University of California, San Diego. He is best known for his books on design, especially The Design of Everyday Things. He is widely regarded for his expertise in the fields of design, usability engineering, and cognitive science, and has shaped the development of the field of cognitive systems engineering. He is a co-founder of the Nielsen Norman Group, along with Jakob Nielsen. He is also an IDEO fellow and a member of the Board of Trustees of IIT Institute of Design in Chicago. He also holds the title of Professor Emeritus of Cognitive Science at the University of California, San Diego. Norman is an active Distinguished Visiting Professor at the Korea Advanced Institute of Science and Technology (KAIST), where he spends two months a year teaching.
Usability can be described as the capacity of a system to provide a condition for its users to perform the tasks safely, effectively, and efficiently while enjoying the experience. In software engineering, usability is the degree to which a software can be used by specified consumers to achieve quantified objectives with effectiveness, efficiency, and satisfaction in a quantified context of use.
Jakob Nielsen is a Danish web usability consultant, human–computer interaction researcher, and co-founder of Nielsen Norman Group. He was named the “guru of Web page usability” in 1998 by The New York Times and the “king of usability” by Internet Magazine.
A heuristic evaluation is a usability inspection method for computer software that helps to idHentify usability problems in the user interface design. It specifically involves evaluators examining the interface and judging its compliance with recognized usability principles. These evaluation methods are now widely taught and practiced in the new media sector, where user interfaces are often designed in a short space of time on a budget that may restrict the amount of money available to provide for other types of interface testing.
ISO 9241 is a multi-part standard from the International Organization for Standardization (ISO) covering ergonomics of human-system interaction and related, human-centered design processes. It is managed by the ISO Technical Committee 159. It was originally titled Ergonomic requirements for office work with visual display terminals (VDTs). From 2006 onwards, the standards were retitled to the more generic Ergonomics of Human System Interaction.
User-centered design (UCD) or user-driven development (UDD) is a framework of processes in which usability goals, user characteristics, environment, tasks and workflow of a product, service or process are given extensive attention at each stage of the design process. This attention includes testing which is conducted during each stage of design and development from the envisioned requirements, through pre-production models to post production. Testing is beneficial as it is often difficult for the designers of a product to understand the experiences of first-time users and each user's learning curve. UCD is based on the understanding of a user, their demands, priorities and experiences, and can lead to increased product usefulness and usability. UCD applies cognitive science principles to create intuitive, efficient products by understanding users' mental processes, behaviors, and needs.
Interaction design, often abbreviated as IxD, is "the practice of designing interactive digital products, environments, systems, and services." While interaction design has an interest in form, its main area of focus rests on behavior. Rather than analyzing how things are, interaction design synthesizes and imagines things as they could be. This element of interaction design is what characterizes IxD as a design field, as opposed to a science or engineering field.
A usability lab is a place where usability testing is done. It is an environment where users are studied interacting with a system for the sake of evaluating the system's usability.
User experience (UX) is how a user interacts with and experiences a product, system or service. It includes a person's perceptions of utility, ease of use, and efficiency. Improving user experience is important to most companies, designers, and creators when creating and refining products because negative user experience can diminish the use of the product and, therefore, any desired positive impacts. Conversely, designing toward profitability as a main objective often conflicts with ethical user experience objectives and even causes harm. User experience is subjective. However, the attributes that make up the user experience are objective.
Web usability of a website consists of broad goals of usability, presentation of information, choices made in a clear and concise way, a lack of ambiguity and the placement of important items in appropriate areas as well as ensuring that the content works on various devices and browsers.
Iterative design is a design methodology based on a cyclic process of prototyping, testing, analyzing, and refining a product or process. Based on the results of testing the most recent iteration of a design, changes and refinements are made. This process is intended to ultimately improve the quality and functionality of a design. In iterative design, interaction with the designed system is used as a form of research for informing and evolving a project, as successive versions, or iterations of a design are implemented.
A website wireframe, also known as a page schematic or screen blueprint, is a visual guide that represents the skeletal framework of a website. The term wireframe is taken from other fields that use a skeletal framework to represent 3-dimensional shape and volume. Wireframes are created for the purpose of arranging elements to best accomplish a particular purpose. The purpose is usually driven by a business objective and a creative idea. The wireframe depicts the page layout or arrangement of the website's content, including interface elements and navigational systems, and how they work together. The wireframe usually lacks typographic style, color, or graphics, since the main focus lies in functionality, behavior, and priority of content. In other words, it focuses on what a screen does, not what it looks like. Wireframes can be pencil drawings or sketches on a whiteboard, or they can be produced by means of a broad array of free or commercial software applications. Wireframes are generally created by business analysts, user experience designers, developers, visual designers, and by those with expertise in interaction design, information architecture and user research.
User experience design, upon which is the centralized requirements for "User Experience Design Research", defines the experience a user would go through when interacting with a company, its services, and its products. User experience design is a user centered design approach because it considers the user's experience when using a product or platform. Research, data analysis, and test results drive design decisions in UX design rather than aesthetic preferences and opinions, for which is known as UX Design Research. Unlike user interface design, which focuses solely on the design of a computer interface, UX design encompasses all aspects of a user's perceived experience with a product or website, such as its usability, usefulness, desirability, brand perception, and overall performance. UX design is also an element of the customer experience (CX), and encompasses all design aspects and design stages that are around a customer's experience.
A user interface specification is a document that captures the details of the software user interface into a written document. The specification covers all possible actions that an end user may perform and all visual, auditory and other interaction elements.
Tools, devices or software must be evaluated before their release on the market from different points of view such as their technical properties or their usability. Usability evaluation allows assessing whether the product under evaluation is efficient enough, effective enough and sufficiently satisfactory for the users. For this assessment to be objective, there is a need for measurable goals that the system must achieve. That kind of goal is called a usability goal. They are objective criteria against which the results of the usability evaluation are compared to assess the usability of the product under evaluation.
User research focuses on understanding user behaviors, needs and motivations through interviews, surveys, usability evaluations and other forms of feedback methodologies. It is used to understand how people interact with products and evaluate whether design solutions meet their needs. This field of research aims at improving the user experience (UX) of products, services, or processes by incorporating experimental and observational research methods to guide the design, development, and refinement of a product. User research is used to improve a multitude of products like websites, mobile phones, medical devices, banking, government services and many more. It is an iterative process that can be used at anytime during product development and is a core part of user-centered design.
Hardware interface design (HID) is a cross-disciplinary design field that shapes the physical connection between people and technology in order to create new hardware interfaces that transform purely digital processes into analog methods of interaction. It employs a combination of filmmaking tools, software prototyping, and electronics breadboarding.