User Interface Designing : Human Factors

Human factors science or human factors technologies is a multidisciplinary field incorporating contributions from psychology, engineering, industrial design, graphic design, statistics, operations research and anthropometric. This term covers:

• Scientific understanding of the properties of human capability (Human Factors Science).
• The application of this understanding to the design, development and deployment of systems and services (Human Factors Engineering).
• The art of ensuring successful application of Human Factors Engineering to a program (sometimes referred to as Human Factors Integration). It can also be called ergonomics.

In general, a human factor is a physical or cognitive property of an individual or social behavior which is specific to humans and influences functioning of technological systems as well as human-environment equilibrium.

Human Factors in User Interface Design

Human factor in interface designing is a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of major phenomena surrounding them. This is a well known subject of Human Factors within the Engineering field. There are many different ways to determine human computer interaction at the user interface by usability testing. Thus a new branch Human Computer Interaction.

Human–computer Interaction (HCI) involves the study, planning, and design of the interaction between people (users) and computers.The term was coined by Card, Moran, and Newell in their germinal book, "The Psychology of Human-Computer Interaction."

Interaction between users and computers occurs at the user interface (or simply interface), which includes both software and hardware.

Basics of User Interface

               The user interface, in the industrial design field of human–machine interaction, is the space where interaction between humans and machines occurs. The goal of interaction between a human and a machine at the user interface is effective operation and control of the machine, and feedback from the machine which aids the operator in making operational decisions. 

          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.

          A user interface is the system by which people (users) interact with a machine. The user interface includes hardware (physical) and software (logical) components. User interfaces exist for varioussystems, and provide a means of:

• Input, allowing the users to manipulate a system
• Output, allowing the system to indicate the effects of the users' manipulation

         Generally, the goal of human-machine interaction engineering is to produce a user interface which makes it easy, efficient, and enjoyable to operate a machine in the way which produces the desired result. This generally means that the operator needs to provide minimal input to achieve the desired output, and also that the machine minimizes undesired outputs to the human.

Other terms for user interface include human–computer interface (HCI) and man–machine interface (MMI).

User interfaces in computing

In computer science and human-computer interaction, the user interface (of a computer program) refers to the graphical, textual and auditory information the program presents to the user, and the control sequences (such as keystrokes with the computer keyboard, movements of the computer mouse, and selections with the touchscreen) the user employs to control the program.

Types

Direct manipulation interface is the name of a general class of user interfaces that allow users to manipulate objects presented to them, using actions that correspond at least loosely to the physical world.

Currently (as of 2009) the following types of user interface are the most common:

• Graphical user interfaces (GUI) accept input via devices such as computer keyboard and mouse and provide articulated graphical output on the computer monitor. There are at least two different principles widely used in GUI design: Object-oriented user interfaces (OOUIs) and application oriented interfaces^{[verification needed]}.
• Web-based user interfaces or web user interfaces (WUI) are a subclass of GUIs that accept input and provide output by generating web pages which are transmitted via the Internet and viewed by the user using a web browser program. Newer implementations utilize Java, AJAX, Adobe Flex, Microsoft .NET, or similar technologies to provide real-time control in a separate program, eliminating the need to refresh a traditional HTML based web browser. Administrative web interfaces for web-servers, servers and networked computers are often called control panels.
• Touchscreens are displays that accept input by touch of fingers or a stylus. Used in a growing amount of mobile devices and many types of point of sale, industrial processes and machines, self-service machines etc.

User interfaces that are common in various fields outside desktop computing:

• Command line interfaces, where the user provides the input by typing a command string with the computer keyboard and the system provides output by printing text on the computer monitor. Used by programmers and system administrators, in engineering and scientific environments, and by technically advanced personal computer users.

• Touch user interface are graphical user interfaces using a touchpad or touchscreen display as a combined input and output device. They supplement or replace other forms of output with hapticfeedback methods. Used in computerized simulators etc.

Other types of user interfaces:

• Attentive user interfaces manage the user attention deciding when to interrupt the user, the kind of warnings, and the level of detail of the messages presented to the user.
• Batch interfaces are non-interactive user interfaces, where the user specifies all the details of the batch job in advance to batch processing, and receives the output when all the processing is done. The computer does not prompt for further input after the processing has started.
• Conversational Interface Agents attempt to personify the computer interface in the form of an animated person, robot, or other character (such as Microsoft's Clippy the paperclip), and present interactions in a conversational form.
• Crossing-based interfaces are graphical user interfaces in which the primary task consists in crossing boundaries instead of pointing.
• Gesture interfaces are graphical user interfaces which accept input in a form of hand gestures, or mouse gestures sketched with a computer mouse or a stylus.
• Intelligent user interfaces are human-machine interfaces that aim to improve the efficiency, effectiveness, and naturalness of human-machine interaction by representing, reasoning, and acting on models of the user, domain, task, discourse, and media (e.g., graphics, natural language, gesture).
• Motion tracking interfaces monitor the user's body motions and translate them into commands, currently being developed by Apple^[1]
• Multi-screen interfaces, employ multiple displays to provide a more flexible interaction. This is often employed in computer game interaction in both the commercial arcades and more recently the handheld markets.
• Noncommand user interfaces, which observe the user to infer his / her needs and intentions, without requiring that he / she formulate explicit commands.
• Object-oriented user interfaces (OOUI) are based on object-oriented programming metaphors, allowing users to manipulate simulated objects and their properties.
• Reflexive user interfaces where the users control and redefine the entire system via the user interface alone, for instance to change its command verbs. Typically this is only possible with very rich graphic user interfaces.
• Tangible user interfaces, which place a greater emphasis on touch and physical environment or its element.
• Task-Focused Interfaces are user interfaces which address the information overload problem of the desktop metaphor by making tasks, not files, the primary unit of interaction
• Text user interfaces are user interfaces which output text, but accept other form of input in addition to or in place of typed command strings.
• Voice user interfaces, which accept input and provide output by generating voice prompts. The user input is made by pressing keys or buttons, or responding verbally to the interface.
• Natural-Language interfaces - Used for search engines and on webpages. User types in a question and waits for a response.
• Zero-Input interfaces get inputs from a set of sensors instead of querying the user with input dialogs.
• Zooming user interfaces are graphical user interfaces in which information objects are represented at different levels of scale and detail, and where the user can change the scale of the viewed area in order to show more detail.

Properties of a good user interface is Consistency and Usability.

Usability : The design of a user interface affects the amount of effort the user must expend to provide input for the system and to interpret the output of the system, and how much effort it takes to learn how to do this. Usability is the degree to which the design of a particular user interface takes into account the human psychology and physiology of the users, and makes the process of using the system effective, efficient and satisfying.

Usability is mainly a characteristic of the user interface, but is also associated with the functionalities of the product and the process to design it. It describes how well a product can be used for its intended purpose by its target users with efficiency, effectiveness, and satisfaction, also taking into account the requirements from its context of use.

Consistency : Good user interface design is about getting a user to have a consistent set of expectations, and then meeting those expectations.

There are three aspects identified as relevant to consistency.

First, the controls for different features should be presented in a consistent manner so that users can find the controls easily.For example, users find it difficult to use software when some commands are available through menus, some through icons, some through right-clicks, some under a separate button at one corner of a screen, some grouped by function, some grouped by “common,” some grouped by “advanced.” A user looking for a command should have a consistent search strategy for finding it. The more search strategies a user has to use, the more frustrating the search will be. The more consistent the grouping, the easier the search. The principle of monotony of design in user interfaces states that ideally there should be only way to achieve a simple operation, to facilitate habituation to the interface.

Second, there is the "principle of least astonishment". Various features should work in similar ways. For example, some features in Adobe Acrobat are "select tool, then select text to which apply." Others are "select text, then apply action to selection." Commands should work the same way in all contexts.

Third, consistency counsels against user interface changes version-to-version. Change should be minimized, and forward-compatibility should be maintained. Generally, less mature software has fewer users who are entrenched in the status quo. Older, more broadly used software must more carefully hew to the status quo to avoid disruptive costs. For example, the change from the menu bars of Microsoft Office 2003 to the ribbon toolbar of Microsoft Office 2007 caused mixed reactions. The new interface caused rejection among advanced users, who reported losses in productivity, while average users reported improved productivity  and a fairly good acceptance. A usual solution in providing a new user interface is to provide a backwards-compatibility mode, so that a product's most intensive users are not forced to bear the costs of the change. A second strategy is to introduce big changes in small increments, so that an overall redesign can be achieved without breaking consistency and providing user feedback at any single step.

Some of my favourite User Interface Design Examples :


Tiny Gift

Carl Cox DJ Mixer



Location Based Operating System



Great iPhone Application