Knowledge in Hci
Importance of good design
With today's technology and tools, and our motivation to create really effective and usableinterfaces and screens, why do we continue to produce systems that are inefficient and confusing or, at worst, just plain unusable? Is it because:• We don't care?• We don't possess common sense?• We don't have the time?• We still don't know what really makes good design?• But we never seem to have time to find out what makes good design, nor to properly apply it. After all, many of us have other things to do in addition to designing interfacesand screens.• So we take our best shot given the workload and time constraints imposed upon us. The result, too often, is woefully inadequate.• Interface and screen design were really a matter of common sense, we developers would have been producing almost identical screens for representing the real world.• Example bad designs– Closed door with complete wood– suggestion : glass doorTHE IMPORTANCE OF THE USER INTERFACE A well-designed interface and screen is terribly important to our users. It is their window to view the capabilities of the system. It is also the vehicle through which many critical tasks are presented. These tasks often have a direct impact on an organization's relations with its customers, and itsprofitability. A screen's layout and appearance affect a person in a variety of ways. If they are confusing and inefficient, people will have greater difficulty in doing their jobs andwill make more mistakes. Poor design may even chase some people away from a system permanently. It can also lead to aggravation, frustration, and increased stress.The Benefits of Good Design Poor clarity forced screen users to spend one extra second per screen.o Almost one additional year would be required to process all screens.o Twenty extra seconds in screen usage time adds an additional 14 person
Dushyant Jodha
Brief history of screen design
A BRIEF HISTORY OF SCREEN DESIGN• While developers have been designing screens since a cathode ray tube display was first attached to a computer, more widespread interest in the application of good designprinciples to screens did not begin to emerge until the early 1970s, when IBM introduced its 3270 cathode ray tube text-based terminal.• A 1970s screen often resembled the one pictured in Figure.It usually consisted of many fields (more than are illustrated here) with very cryptic and often unintelligible captions.• It was visually cluttered, and often possessed a command field that challenged the user to remember what had to be keyed into it.• Ambiguous messages often required referral to a manual to interpret.• Effectively using this kind of screen required a great deal of practice and patience.• Most early screens were monochromatic, typically presenting green text on black backgrounds.• At the turn of the decade guidelines for text-based screen design were finally made widely available and many screens began to take on a much less cluttered lookthrough concepts such as grouping and alignment of elements, as illustrated in Figure
Popularity of graphics
• A graphical screen bore scant resemblance to its earlier text-based colleagues.• Older text-based screen possessed a one dimensional• Graphic screens assumed a three-dimensional look.• Controls appeared to rise above the screen and move when activated.• Information could appear, and disappear, as needed.• Text could be replaced by graphical images called icons.• These icons could represent objects or actions• selection fields such as radio buttons, check boxes, list boxes, and palettes coexisted with the reliable old text entry field• More sophisticated text entry fields with attached or dropdown menus of.• Objects and actions were selected through use of pointing mechanisms.• Increased computer power.• User's actions to be reacted to quickly, dynamically, and meaningfully.• WIMP interface: windows, icons, menus, and pointers.• Graphic presentation is much more effective than other presentation methods.• Properly used, it reduces the requirement for perceptual and mental information recoding and reorganization, and also reduces the memory loads.• It permits faster information transfer between computers and people by permitting more visual comparisons of amounts, trends, or relationships; more compact representation of information;• Graphics also can add appeal or charm to the interface and permit greater customization to create a unique corporate or organization style.GRAPHICAL SYSTEMS ADVANTAGES AND DISADVANTAGES• Reduce the memory requirements.• More effective use of one's information.• Dramatically reduce system learning requirements.• Experience indicates that for many people they have done all these things.ADVANTAGES Symbols recognized faster than text Faster learning Faster use and problem solving Easier remembering More natural Exploits visual/spatial cues Fosters more concrete thinking Provides context Fewer errors Increased feeling of control
Concurrent performance of function
CONCURRENT PERFORMANCE OF FUNCTIONSGraphic systems may do two or more things at one time. Multiple programs may run simultaneously. When a system is not busy on a primary task, it may process backgroundtasks (cooperative multitasking).When applications are running as truly separate tasks, thesystem may divide the processing power into time slices and allocate portions to each application.Data may also be transferred between programs. It may be temporarily stored on a "clipboard" for later transfer or be automatically swapped between programs.THE GRAPHICAL USER INTERFACE A user interface is a collection of techniques and mechanisms to interact with something. In a graphical interface the primary interaction mechanism is a pointing device of some kind. This device is the electronic equivalent to the human hand. What the user interacts with is a collection of elements referred to as objects. They can be seen, heard, touched, or otherwise perceived. Objects are always visible to the user and are used to perform tasks. They are interacted with as entities independent of all other objects. People perform operations, called actions, on objects. The operations include accessing and modifying objects by pointing, selecting, and manipulating. All objects have standard resulting behaviors.THE WEB USER INTERFACEThe expansion of the World Wide Web since the early 1990s has been truly amazing. Once simply a communication medium for scientists and researchers, its many and pervasive tentacles have spread deeply into businesses, organizations, and homes around the world.Unlike earlier text-based and GUI systems that were developed and nurtured in an organization's Data Processing and Information Systems groups, the Web's roots were sown in a market-driven society thirsting for convenience and information.Web interface design is essentially the design of navigation and the presentation of information. It is about content, not data.Proper interface design is largely a matter of properly balancing the structure and relationships of menus, content, and other linked documents or graphics. The design goal is
Principle of user interface
PRINCIPLES OF USER INTERFACE DESIGN• An interface must really be just an extension of a person. This means that the system and its software must reflect a person's capabilities and respond to his or her specificneeds.• It should be useful, accomplishing some business objectives faster and more efficiently than the previously used method or tool did.• It must also be easy to learn, for people want to do, not learn to do.• Finally, the system must be easy and fun to use, evoking a sense of pleasure and accomplishment not tedium and frustration.• The interface itself should serve as both a connector and a separator• a connector in that it ties the user to the power of the computer, and a separator in that it minimizes the possibility of the participants damaging one another.
Principle of the xerox star
PRINCIPLES FOR THE XEROX STAR• The design of the Xerox STAR was guided by a set of principles that evolved over its lengthy development process. These principles established the foundation for graphical interfaces.• Displaying objects that are selectable and manipulable must be created.• A design challenge is to invent a set of displayable objects that are represented meaningfully and appropriately for the intended application.• It must be clear that these objects can be selected, and how to select them must be Self-evident.• When they are selected should also be obvious, because it should be clear that the selected object will be the focus of the next action. Standalone icons easily fulfilled this requirement.• The handles for windows were placed in the borders.• Visual order and viewer focus: Attention must be drawn, at the proper time, to the important and relevant elements of the display. Effective visual contrast between various components of the screen is used to achieve this goal. Animation is also used to draw attention, as is sound.
Some points
Familiarity• Employ familiar concepts and use a language that is familiar to the user.• Keep the interface natural, mimicking the user's behavior patterns.• Use real-world metaphors.Forgiveness• Tolerate and forgive common and unavoidable human errors.• Prevent errors from occurring whenever possible.• Protect against possible catastrophic errors.• When an error does occur, provide constructive messages.•Predictability• The user should be able to anticipate the natural progression of each task.o Provide distinct and recognizable screen elements.o Provide cues to the result of an action to be performed.• All expectations should be fulfilled uniformly and completely.RecoveryA system should permit:- Commands or actions to be abolished or reversed.- Immediate return to a certain point if difficulties arise.Ensure that users never lose their work as a result of:- An error on their part.- Hardware, software, or communication problemsResponsivenessThe system must rapidly respond to the user's requests Provide immediate acknowledgment for all user actions:- Visual.- Textual- Auditory.TransparencyPermit the user to focus on the task or job, without concern for the mechanics of the interface.- Workings and reminders of workings inside the computer should be invisible to the user.SimplicityProvide as simple an interface as possible.Five ways to provide simplicity:
Unit 2
OBSTACLES AND PITFALLS IN DEVELOPMENT PATH• No body ever gets it right for the first time• Development is chock full of surprises.• Good design requires living in a sea of changes.• Designers need good tools.• Performance design goals• People may make mistakes while using a good system alsoCOMMON PITFALLS• No early analysis and understanding the users needs and expectations.• A focus on using design features or components .• No usability testing.• No common design team vision.• Poor communicationCOMMON USABILITY PROBLEMS• Ambiguous menus and icons.• Languages that permit only single direction movement through a system.• Input and direct manipulation limits.• Complex linkage.• Inadequate feedback.• Lack of system anticipation.• Inadequate error messages.IRRITATING CHARACTERS• Visual clutter• Impaired information readability• Incomprehensible components• Annoying distractions.• Confusing navigation.• Inefficient operations• Inefficient page scrolling.• Information overload
Human interaction with computer
HUMAN INTERACTION WITH COMPUTERSUnderstanding How People Interact with Computers Characteristics of computer systems, past and present, that have caused, and are causing, people problems. We will then look at the effect these problems have –• Why people have trouble with computers• Responses to poor design• People and their tasksWhy People Have Trouble with Computers• Extensive technical knowledge but little behavioral training.• With its extensive graphical capabilities.• Poorly designed interfaces.• What makes a system difficult to use in the eyes of its user?• Use of jargon• Non-obvious design• Fine distinctions• Disparity in problem-solving strategies• an "error-preventing" strategy• Design inconsistencyPSYCHOLOGICALTypical psychological responses to poor design are:• Confusion: Detail overwhelms the perceived structure. Meaningful patterns are difficult to ascertain, and the conceptual model or underlying framework cannot be understood or established.• Annoyance: Roadblocks that prevent a task being completed, or a need from being satisfied, promptly and efficiently lead to annoyance. Inconsistencies in design, slow computer reaction times, difficulties in quickly finding information, outdated
Characteristics of human in design
IMPORTANT HUMAN CHARACTERISTICS IN DESIGN• Importance in design are perception, memory, visual acuity, foveal and peripheral vision, sensory storage, information processing, learning, skill, and individual differences.• Perception• Proximity• Similarity• Matching patterns• Succinctness• Closure• Unity• Continuity• Balance• Expectancies• Context• Signals versus noise• Memory: Memory is not the most stable of human attributes, as anyone who has forgotten why they walked into a room, or forgotten a very important birthday, can attest.• -Short-term, or working, memory.- Long-term memory- Mighty memory- Sensory Storage