HUMAN COMPUTER INTERACTION Mohammad Amin Kuhail M.Sc. (York, UK) Second Semester 07/08  University of Palestine  Faculty of Applied Engineering and Urban Planning  Software Engineering Department  Lecture #: 1  Week: 3  Date: SAT,  Location: KB112  Introduction to HCI

Introduction to Human Computer Interaction  Outline  Definition  Elements  Brief History of GUI  Importance of HCI

Human Computer Interaction Definition  Definition  Human Computer Interaction, or HCI, is the study, planning, and design of what happens when users and computers work together. As its name implies, HCI consists of three parts: the user, the computer itself, and the ways they work together. User Computer Interaction

Human Computer Interaction Definition  Definition  HCI is often regarded as the intersection of computer science, behavioral sciences, design and several other fields of study.  Definition given by the ACM: Human-computer interaction 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.  it draws from supporting knowledge on both the machine and the human side.  On the machine side, techniques in computer graphics, operating systems, programming languages, and development environments are relevant.  On the human side, communication theory, graphic and industrial design disciplines, linguistics, social sciences, cognitive psychology.

Human Computer Interaction Elements  Users  Could be one or a group of users working together, or a series of users involved with some part of job.  The user is whoever is trying to get the job done using the technology.  An appreciation of the way people's sensory systems (sight, hearing, touch) relay information is vital to designing a first-class product.  Display layouts should accommodate the fact that people can be sidetracked by the smallest movement in the outer (peripheral) part of their visual fields, so only important areas should be specified by moving or blinking visuals. And of course, people like designs that grab their attention. Designers must decide how to make products attractive without distracting users from their tasks.

Human Computer Interaction Elements  The Computer  Could be any technology ranging from desktop computers, to large scale computer systems -- even a process control system or an embedded system could be classed as the computer.  For example, if we were discussing the design of a Website, then the Website itself would be referred to as "the computer".

Human Computer Interaction Elements  The Interaction  There are obvious differences between humans and machines. In spite of these, HCI attempts to ensure that they both get on with each other and interact successfully.  For example, In order to achieve a usable Website, you need to apply what you know about humans and computers, and consult with likely users throughout the design process.

Brief History of HCI  1963: Ivan Sutherland’s sketchPad  SketchPad supported manipulation of objects using a light-pen, including grabbing objects, moving them, changing size, and using constraints. It contained the seeds of myriad important interface ideas.  The system was built at Lincoln Labs with support from the Air Force.

Brief History of HCI  1968: William Newman's Reaction Handler  Newman’s Reaction Handler created at Imperial College, London ( ) provided direct manipulation of graphics, and introduced "Light Handles," a form of graphical potentiometer

Brief History of HCI  1968: AMBIT/G System  It employed, among other interface techniques, iconic representations, gesture recognition, dynamic menus, selection of icons by pointing, and moded and mode- free styles of interaction  implemented at MIT's Lincoln Labs, 1968, ARPA funded).

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Brief History of HCI  1975: Smith  Smith coined the term "icons" in his 1975 Stanford PhD thesis on Pygmalion and Smith later popularized icons as one of the chief designers of the Xerox Star  Many of the interaction techniques popular in direct manipulation interfaces, such as how objects and text are selected, opened, and manipulated, resulted from research at Xerox PARC in the 1970's.

Brief History of HCI  1981: Xerox  the first commercial PC designed for “business professionals“ as an office automation system which had overlapping windows.  High quality interface, desktop metaphor, pointing, easy to learn GUI: Bitmapped screen, Windows could overlap, Icons and mouse used, Progressive disclosure.  Direct manipulation

Brief History of HCI  1983: Apple Lisa  text based system, redesign as graphical system similar to Xerox Star but more personal than office tool.  commercial was a failture because of expensive.  Lisa’s interface features: Desktop metaphor Mouse and Windows Multi-tasking

Brief History of HCI  1984: Apple/Steve Jobs – Macintosh  the first commercial graphics destop microcomputer based on Alto and Star, old ideas but well done. With aggressive princing, it was successful commercially.  High quality graphics and laser printer  Good interface guidelines, pulldown menus, icons & toolbars, drag-and-drop  Well written application: MacWrite and MacDraw and third party applications: pgemaker, word, Excel  Partially open architecture and powerful developer’s toolkit

Brief History of HCI  1984: Apple/Steve Jobs – Macintosh

Brief History of HCI  1985 Microsoft – Windows  A Mac imitation with some improvements: collaborative, iterative and multi- disciplinary.

Brief History of HCI  Summary

Importance of HCI   Surveys show that over 50% of the design and programming effort on projects is devoted to the user interface portion.  There is substantial empirical evidence that employing the processes, techniques, and tools developed by the HCI community can dramatically decrease costs and increase productivity.  For example, one study reported savings due to the use of usability engineering of $41,700 in a small application used by 23,000 marketing personnel, and $6,800,000 for a large business application used by 240,000 employees.  Savings were attributed to decreased task time, fewer errors, greatly reduced user disruption, reduced burden on support staff, elimination of training, and avoidance of changes in software after release.

Importance of HCI   A usability analysis of a proposed workstation saved a telephone company $2 million per year in operating costs.  A mathematical model based on eleven studies suggests that using software that has undergone thorough usability engineering will save a small project $39,000, a medium project $613,000 and a large project $8,200,000  There are also well-known catastrophes that have resulted from not paying enough attention to the human-computer interface.  the US Stark's inability to cope with Iraqi Exocet missiles was partly attributed to the human-computer interface  Problems with the interfaces of military and commercial airplane cockpits have been named as a likely cause for several crashes, including the Cali crash of December 1995

Importance of HCI   The recognition of their importance in other disciplines is increasing and with it the necessary interdisciplinary collaboration needed to fully address many challenging research problems.  For example, for artificial intelligence technologies such as agents, speech, and learning and adaptive systems, effective interfaces are fundamental to general acceptance.  New programming languages such as Java result from the need to program new types of distributed interfaces on multiple platforms.

Introduction to HCI  References [1] [2] [3] [4]

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