Computer system and interface architecture

The specialized components computers have for interacting with people

• Input and output devices

– mechanics and characteristics of particular hardware devices, performance characteristics (human and system), esoteric devices, virtual devices

• Dialogue techniques

– the basic software architecture and techniques for interacting with humans

• e.g. dialog inputs and outputs; interaction styles; issues

•Computer graphics

– basic concepts from computer graphics that are especially useful to HCI

• Dialogue architecture

– software architecture and standards for interfaces

• e.g., screen imaging; window managers; interface toolkits; multi-user architectures, look and feel, standardization and interoperability

Aims of HCI

HCI seeks to provide a better understanding of both the human user and the computer system, in an effort to make the interactions between the two easier and satisfying.

• Develop applications that enable user to perform their tasks more efficiently through good user interface.

• Good user interface may result in:

– Increased productivity

– Reduced training costs

– Preventable (life-threatening) user errors

– Reduced employee turnover

– User satisfaction

– Higher quality products produced

To understand the human as an information-processing system,how humans communicate, and people’s physical and psychological requirements

• Human information processing

– characteristics of the human as a processor of information

• memory, perception, motor skills, attention, problem-solving, learning and skill acquisition, motivation, conceptual models, diversity...

• Language, communication and interaction

– aspects of language

• syntax, semantics, pragmatics; conversational interaction, specialized languages

•Ergonomics

– anthropometric and physiological characteristics of people and their relationship to workspace and the environment

• arrangement of displays and controls; cognitive and sensory limits; effects of display technology; fatigue and health; furniture and lighting; design for stressful and hazardous environments; design for the disabled...

What is HCI?

HCI involves the design, implementation and evaluation of interactive systems in the context of the user's task and work.‘

• Human-Computer Interaction is not just about a single user and a desktop computer.

• The user might be an individual, group of people, or a sequence of users dealing with a task.

• The computer might be a desktop computer, large-scale computer, embedded computer, process control system, . . .

• Interaction could be direct or indirect communication between the two.

• The term HCI is young and the discipline has its base in ergonomics (or human factors) and man-machine interaction ( Interface).

Who is involved in HCI?

Multi disciplinary involving:

– cognitive psychology,cognitive science,

– social & organisational psychology,

– linguistics,artificial intelligence,

– philosophy,sociology & anthropology,

– Engineering ,computer science,

– graphic design,

– marketing . . .

In other words:

– Computer Science & Eng to be able to build the technology

– Psychology & cognitive science to give her knowledge of the user’s perceptual, cognitive & problem solving skills

– Ergonomics for the user physical capabilities

– Sociology to help understand the wider context of the interaction

– Graphic Design to produce an effective interface presentation.

Unfortunately cannot have all in only one person. But can identify and apply principles and guidelines from these disciplines that contribute to better system design.

Human Computer Interaction

Why study HCI?

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•Why is “SAVE” button always far from “Delete” Button? ( Try Cancel a cancelled operation)

•What does “User Friendly” stand for you?

•How long do you take to be able to use a new technology

•Consider your mobile phone…why is NOKIA so popular?…besides its numerous features, it does cater for user friendliness! Screen size, buttons layout and carefully labeled buttons.

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•Some User Comments:

"Why can't I view the customer's past ordering history when I am entering a new order?“

"Sometimes I don't know the code of a new product off the top of my head, is there a key I can hit to see the codes on the screen rather than to have to refer to my code printout? I tried Shift-C but it didn't work“

•Some Designer/Analysts response:

“You didn’t tell us that …”

“This was not part of the specfications…”

•HCI (Human Computer Interaction) is a field of study that identifies clearly the fact that in order to achieve certain desired operations, human will have to do so by the help of machines (computers) through what is called an interface.

•Interface:

– The point of interaction or communication between a computer and any other entity, such as a printer or human operator.

– The layout of an application's graphic or textual controls in conjunction with the way the application responds to user activity.

•Hence if we can understand that the interface is the only way to communicate with the machine, we need to ensure that the interface in question does allow for the desired tasks. At the same time taking into consideration abilities and limitations of the user.

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