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Human – the end-user of a program – the others in the organization Computer – the machine the program runs on – often split between clients & servers Interaction – the user tells the computer what they want – the computer communicates results

 Human-Computer Interaction (HCI) is a term refer to the understanding and designing of different relationships between people and computers

system concerned to study, design, construction and implementation of human- centric interactive computer systems

basic goal :improve the interactions between users and computers by making computers more usable and receptive to the user's needs.

A long term goal :is to design systems that minimize the barrier between the human's cognitive model of what they want to accomplish and the computer's understanding of the user's task.

Input and Output Devices Dialogue Techniques Dialogue Genre Application Areas Ergonomics Evaluation Techniques Design Approaches Implementation Techniques and Tools Example Systems and Case Studies Human Language, Communication and Interaction Human Information Processing Use and Context Human-Machine Fit and AdaptationSocial Organization and Work Computer Graphics Dialogue Architecture Development Process A a

1- Human information processing, memory, perception, motor skills, attention, problem-solving, learning and skill acquisition, motivation, conceptual models.

,2-Language, communication and interaction aspects of language - syntax, semantics, pragmatics; conversational interaction, specialized languages

3- Ergonomics anthropometric and physiological characteristics of people and their relationship to workspace and the environment.

Business view: –to use humans more productively/effectively –the human costs now far outweigh hardware and software costs Personal view: –people view computers as appliances, and want it to perform as one

Marketplace view: – everyday people using computers now expect “easy to use system” not tolerant of poorly designed systems – if product is hard to use, people will seek other products

The system view: –complex human –complex computer –complex interface between the two

The human factors view: –humans have limitations –errors are costly in terms of loss of time loss of money loss of morale –design can cope with such limitations !

The social view: Computers contribute to critical parts of our society, and cannot be ignored –educate our children –take medical histories and provide expert advice –keep track of our credit worthiness

 The 1st is concerned with technological innovation to meet the user's particular needs  Better output devices, like display monitors  Improved input devices, like electronic pen

 The 2nd is concerned with the cognitive characteristics (background and knowledge of the users) including: Their knowledge representation, reasoning strategies, and the types of decisions they prefer in solving problems.

 The 3rd is concerned with the tasks which the users wish to carry out.  Is it complex tasks (e.g. controlling a nuclear power station) or simple tasks (e.g. writing letters).  The 4th is concerned with the types of interfaces available.

HCI is undoubtedly a multi-disciplinary subject. The ideal designer of an interactive system would have expertise in a range of topics: psychology and cognitive science to give his knowledge of the users perceptual Cognitive and Problem- solving skills. ergonomics for the user’s physical capabilities

sociology to help her understand the wider context of the interaction. computer science and engineering to be able to build the necessary technology. business to be able to market it Graphic design to produce an effective interface presentation.

technical writing to produce the manuals,

Interaction designers –involved in the design of all the interactive aspects of a product User interface architect –Term often used for member of software team for interface issues Usability engineers –focus on evaluating products, using usability methods and principles

Web designers –develop and create the visual design of websites, such as layouts Information architects –how to plan and structure knowledge rich interactive products

 Unfortunately for us, there is no general and unified theory of HCI that we can present. there is an underlying principle that forms the basis of our own views on HCI,and it is captured in our claim that people use computers to accomplish work.

This outlines the three major issues of concern:  the people  the computers  the tasks that are performed. The system must support the user’s task, which gives us a fourth focus, usability…..

HCI depends on computer operating as an intermediary, achieving appropriate interaction through a variety of I/O devices